Wikipedia talk:Manual of Style/Dates and numbers/Archive 83

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Frequency of conversions

Another point: within an article, is there any consensus on how frequently a metric/Imperial conversion should be made? Consider the following: in an article is written about a subject using the metric system, the same numbers might be brought up again and again (for example, gun characteristics in an article about a European battleship). It seems excessive and distracting to repeatedly convert the same number in one article. Isn't it sufficient to convert any particular metric number to Imperial once in the article, once in the infobox, and leave it at that? The same rule would apply to articles about subjects using the Imperial system. The conversion is spelled out for anyone who wants to know, but it needn't intrude every single time the same number is mentioned -- people should be able to remember that 38.1 cm (15") -- or vice-versa -- over the length of a reasonable-length article. I apologise if this issue has already been raised and resolved. Sacxpert 20:00, 1 September 2007 (UTC)

Yes, it is a clutter, and no, it hasn't been resolved. I would think they should be used chiefly only when the unit is first used in an article, and on all characteristics in a Specifications section, if there is one. As for infoboxes, the associated WikiProject should determine the defaults; I don't think a narrow infobox is the right place to cram in conversions. Askari Mark (Talk) 20:38, 1 September 2007 (UTC)

I agree—it's worth including this. What about this wording, as a third exception to the "generally provide conversions" rule?

• Conversions to and from metric and imperial/US units are generally provided. There are two three exceptions:
  • scientific articles where there is consensus among the contributors not to convert the metric units, in which case the first occurrence of each unit should be linked;
  • where inserting a conversion would make a common expression awkward (“The four-minute mile”);
  • subsequent appearances of exactly the same value and unit in an article, where a repetition of the conversion appears to be unnecessary.

Tony 06:35, 2 September 2007 (UTC)

I oppose a guideline limiting a conversion to one per article. Some articles have multiple values of multiple units (square feet, gallons, acre feet, acres, 'cfs', 'fps' 'bcf', 'bbl'). Metric readers should not be given memory work to read an article just because non-metric/domain-specialist readers feel uncomfortable/unfamiliar with multiple metric conversions. I think it would be difficult to come up with a reasonable guideline, nor do I think one is necessary. Lightmouse 10:22, 2 September 2007 (UTC)

I agree with Tony on his proposal. We should be streamlining units, and using them consistently. I would also point out to Lightmouse that this cuts both ways between metric and Imperial: if an article's subject is within a SI context, there would only be one conversion to Imperial units in the article, for every specific numerical value. The idea here is not to convert only a single incident of, for example, inches to centimetres, but rather to convert the specific value of 10.5 cm to 4.1 inches only once in the article. This seems reasonable, especially since the same numbers can crop up over and over again in the same article; it gets length and tedious. If someone wants to know and can't remember, they can back to the first appearance of the number -- that's not an unreasonable burden. Example:

The 38 cm (15 in) guns of the "Bismarck" class were a reasonable compromise, delivering superb hitting power, even compared to the 40.6 cm (16 in) guns in use by other navies.... [new paragraph] The 38 cm turrets were arranged fore and aft, supplemented by 15 cm (5.9 in) secondary weapons abeam. A total of eight 38 cm and twelve 15 cm weapons were fitted to the battleship. Sacxpert 19:52, 2 September 2007 (UTC)

I have no problem with you editing articles in the way you suggest. This is a rare issue that is easily solved without a guideline. However, the guideline as proposed could be abused by metric hostile editors to strip out non-adjacent conversions. Lightmouse 18:36, 3 September 2007 (UTC)

Please believe me when I say I'd like to get consensus and move on, but I can't help but observe that the particular naval example used here has conflicts even with customary metric usage in the specific field. While I can't immediately find the NATO Standardization Agreement on artillery, which I believe specifies millimeters, virtually any modern military document will speak of artillery (and small arms) calibers in millimeters, not centimeters. The Soviet Union also standardized on millimeters. The most common artillery piece in the world is called the 155mm, not the 15.5cm. Centimeters were used in some older references, which I'd estimate were early 20th century. It worries me that we may be getting into edit wars over metric purity. Apropos of such wars, I am still baffled by the notion that every article will be accessible to a nonspecialist. Surely the article on Covalent bond is not accessible to a reader with a more than trivial knowledge of physical chemistry, the article on Fourier transform is not accessible to a reader unfamiliar with mathematical analysis, and the article on Tumor necrosis factor-alpha is not accessible to a reader not conversant with the foundations of immunology and molecular genetics. Howard C. Berkowitz 18:56, 3 September 2007 (UTC)

I like Tony's formulation and Sacxpert gives an excellent example why. However, I would also like to point out that "number-rich" sentences, paragraphs and sometimes subsections (chiefly introductions) often become very cluttered and difficult to read, and repetitions of the same number/unit aren't usually the cause. I've been increasingly tempted to propose excluding conversions from at least the intro, since they'll all be encountered in the subsequent text. Askari Mark (Talk) 19:01, 3 September 2007 (UTC)

Interesting point, Howard. You're right about the earlier-in-the-century centimetre/millimetre usages. Up through the Nazi era, the Germans, for one, described all of their artillery in terms of centimetres, not millimetres. I don't know the practice of most other metric militaries in that era. Parlance should probably follow the standard of the force using it, I suppose, although I think that either cm or mm is an appropriate choice. Your point about non-specialist access is also well-taken: I've come across plenty of astrophysics articles that are off into territory far beyond my ken in just a dozen sentences. This applies to the next section heading, too. I have to say that Lightmouse's perspective about "metric-hostile" editors is perhaps a bit overwrought, and ignores the converse: Imperial-hostile editors. One conversion for each occurrence of any given unit should be enough in the entire article, whether its metric-to-Imperial or vice-versa. As I said before, if someone really wants to know that 15 cm (or 150 mm) converts to 5.9 inches, and can't remember that from the previous section, they can hit the "page up" key a few times; it won't kill them. I also think Askari Mark might be on the right track; the introduction is no place for dozens of conversions, especially if they'll be coming up again. Then again, most introductory sections to Wikipedia articles are far too long, in any case, and better article formatting should reduce that problem, to some degree. Would I be correct in saying that we are approaching a consensus to support Tony's proposal? Sacxpert 21:19, 3 September 2007 (UTC)

If I might be forgiven a personal anecdote, which is even worse, I suppose, than Original Research, it happens that I've only very recently had occasion to work with customary nautical units. Before some recent business opportunities where I have been working with software for commercial fishing, my nautical experience was much more in how to defend a carrier battle group against a determined Soviet attack, and what I knew about boats was that the pointy end went forward (most of the time). In the former situation, the concern was much more seconds to impact than whether the missile speed was in knots or km/hour. It tended to be more a question of intercept geometry and fuel consumption to know if someone could outrun a torpedo. So, I'm really not coming into metrication with a prejudice, and, as a one-time biochemist, I'm quite comfortable with such units.

Now, however, I am dealing with such things as international fisheries regulation, and a very basic surveillance rule is that a scallop dredge, for example, will not work if towed at more than 5 knots, and this is a parameter that is set whether it's a French, Russian, American, or German Vessel Monitoring System.

As far as Tony's proposal, might I get a sense of whether his second point, "**where inserting a conversion would make a common expression awkward (“The four-minute mile”);" applies to situations where non-SI units are customary or indeed explicit, such as knots as a nautical speed, or the 12 nm[i] territorial limit and 200 nm[i] Exclusive Economic Zone as specified in the United Nations Convention on Law of the Sea (UNCLOS)? Is this another way of stating his second point, or is it a fourth that might be added? Howard C. Berkowitz 23:53, 3 September 2007 (UTC)

I too oppose a once per article guideline. I would like to see Tony's proposal be a less ambiguous. What about: "• subsequent appearances of exactly the same value and unit within the same paragraph in an article"?

I would also add "Where the same value and unit appears multiple times in a table the value should be converted each time." I added this so that readers don't have to search through columns of figures to find the conversion they are looking for. -- PatLeahy (talk) 00:23, 4 September 2007 (UTC)

I too am not crazy about giving explicit guidance on the once per article clause. I feel better PatLeahy's proposal above. However, with any proposal above, there should be the clause, "when there is consensus to do so". —MJCdetroit 00:48, 4 September 2007 (UTC)

• (outdent) Not thrilled about the "with consensus" clause, unless really necessary. It's like all of the globally assumed principles (don't mess with quoted material, options by consensus, be consistent within an article)—let's not clutter the MOS where unnecessary. What about the following text, then, after Patleahy's suggestion:

• • subsequent appearances of exactly the same value and unit where a repetition of the conversion appears to be unnecessary.

I'm OK about having nothing at all, though.

Tony 04:09, 4 September 2007 (UTC)

I would like "nothing at all". Sacxpert initially raised this issue on my talk page, I accepted the principle and suggested raising it here. The first metric edits of many articles will inevitably need fine tuning by subsequent edits. This is already permitted by the MOS and there is no new issue for the MOS to resolve. This issue is not a significant cause of edit warring. A guideline would be complicated and probably would have little effect on edits anyway. Worse, it could be misused or misunderstood. Lightmouse 10:40, 4 September 2007 (UTC)

May I ask, then, Lightmouse, what do you consider the source of edit wars related to metrication, and how may the wars be minimized? I've become sensitized to this issue not because I routinely use Imperial or other non-SI units in articles not related to nautical matters, but because I'm now doing a good deal in the nautical area and, to some extent, I feel under bombardment by 6 inch/152 millimeter howitzers.

Last night, I was discussing this area with a commercial fisherman colleague, and the term fathometer came up. In Wikipedia, this redirects to Fishfinder, which is incorrect as fathometers may simply be used for finding the depth for navigational purposes, and not be concerned with fish. I'm not being completely facetious to ask how entries with non-metric terms in their very names should be handled. In this case, the depth markings on many nautical charts are not in meters or feet, but in fathoms. Should "fathometer" itself be deprecated, perhaps along with "yardstick?" Please accept my word that I am not looking for a war on this topic, but I feel, to some extent, in an edit war when I write a nautical article and find it quickly edited with conversions.

As has been mentioned by others, not all articles can be accessible, beyond the first few sentences, to people without at least a grounding in the subject. Metrication is fairly easy to insert although too many conversions make for awkward writing, but articles in astrophysics, molecular pharmacology, mathematics, etc., are not and can never be accessible to the general reader. In the nautical articles, given that charts and other safety-of-life material (see International Convention for the Safety of Life at Sea (SOLAS) and the United Nations Convention on Law of the Sea (UNCLOS); the latter, in which metric nations certainly participated, specified boundaries in nautical miles.Howard C. Berkowitz 11:13, 4 September 2007 (UTC)

Also, Lightmouse, what this proposal is trying to do is get people to make "first metric edits" (or "first Imperial edits", b/c you keep forgetting about Imperial system users who might want access to general articles on metric subjects) with some common sense, rather than swooping down on every single occurrence of 4 inch (102 mm), when 4 in (102 mm) could come up many times in a row. After all, it gets pretty bloody tedious to see 4 in (102 mm) every other sentence. That way, if articles weren't being swept wholesale for conversion, there wouldn't be anything to clean up in the first place. Tony's guideline is vague, but it presents a general principle: don't repeat a conversion if it's not necessary. Conversely, it specifically states "exactly the same value and unit", which is unambiguous, and should not promote this odd misuse and abuse about which you seem to be so concerned. There's nothing complicated about that, and it sends a good-faith message to editors. Sacxpert 16:23, 4 September 2007 (UTC)

Tony's second suggestion is still ambiguous. My suggestion limited removal of redundancy to a single paragraph. If this guideline is not clear it could be interpreted as being once per article. -- PatLeahy (talk) 17:37, 4 September 2007 (UTC)

Howard C. Berkowitz said:

• "what do you consider the source of edit wars related to metrication". I do not know. The phrase 'We fear change' comes to mind. There are few publications quite like Wikipedia.
• Should "fathometer" itself be deprecated. No. I would not ban it on metrication grounds. We do not need to create a guideline for all possible scenarios relating to units. It does appear to be an American term though. You might want to think about that.

Lightmouse, I'm beginning to wonder if you have a bias about things that are "American" or "US-centric" rather than not metricated. Fathom historically is a British term. Look through histories and historical novels of the "Age of Sail", and you will find many references to fathoms. Before electronics existed, the Sounding line was used to measure depth. Sounding lines essentially were ropes with various markings for number of fathoms, and a weight at the leading end. The line would be tossed overboard and the skilled seaman handling it would feel when it hit bottom, and call out the number of fathoms to the bottom (the weight often had soft wax at the end so it could return a sample of the bottom -- sand, mud, etc.). The unit of fathoms, while I freely admit is archaic and non-metricated, significantly preceded the existence of the United States and is still in worldwide common use in nautical operations. !Howard C. Berkowitz 12:41, 5 September 2007 (UTC)

I have a bias against regional terminology and that might sound like anti-<region>. I have no bias against American things. Apologies if that is how it came across. Your analysis of the history of the fathom seems reasonable to me.

• depth markings on many nautical charts are not in meters. That appears to be a US-centric statement.

Again, I am concerned you are calling things US-centric that are also quite common in the UK and elsewhere in the world. Yes, charts are converting to metric depth, but this will happen over a period of quite a number of years. Since the sea bottom changes in depth, charts must be updated based on measurements. The introduction of electronic charts speeds the process of updating. Howard C. Berkowitz 12:41, 5 September 2007 (UTC)

• United Nations Convention on Law of the Sea ... specified boundaries in nautical miles. I am sure that is true. I still think there should be no ban on converting nautical miles into kilometres.

In no way am I proposing a ban. When citing a formal document that uses a non-metric measurement, especially an international document that was prepared with the involvement of experts from countries that are fully metricated, I would propose a metric conversion at the first mention of something like "200 nmi Exclusive Economic Zone", but no further conversion of the same measurement through the rest of the article.Howard C. Berkowitz 12:41, 5 September 2007 (UTC)

You removed metric conversions from Vessel monitoring system and Fisheries management. These edits made me think you do not want nautical miles or knots converted into kilometres and km/h. MJCdetroit has already disagreed with those metric removal edits. Further comments by yourself and others reinforced the belief that somehow kilometres and km/h were being opposed because of the widespread domain specialist and legal use of nautical miles/knots. This conversation seems a bit theoretical, perhaps we should look at an example where a problem arises that is difficult for editors to solve. Lightmouse 14:38, 5 September 2007 (UTC)

I don't understand what you mean by "theoretical". Let me be specific. In articles dealing with domains, such as fisheries and marine navigation, where non-metric units are customary, , I am willing to have the first reference to a non-metric unit have a conversion with it, although it may be quite appropriate to mention, as well, that the non-metric unit is the language of a treaty. I don't want further mentions of the same unit to carry conversions, because I think it makes things hard to read while the conversion information has already been given. The problem is especially acute when referring to nautical miles, knots, and latitude, because the three are related and the reader often needs to see the relationship. Again, I don't mind conversion on the first entry. I do object to editors putting conversions on every subsequent mention of the particular unit and quantity. Howard C. Berkowitz 15:15, 5 September 2007 (UTC)

Thanks for the clarification. I think I understand your position now. Would you mind if those articles Vessel monitoring system and Fisheries management had non-adjacent instances of 5, 12 and 200 nautical miles converted into km? Lightmouse 15:25, 5 September 2007 (UTC)

Sacxpert said:

• you keep forgetting about Imperial system users who might want access to general articles on metric subjects. That is not true, I do not forget about non-metric issues. I am choosing not to speak on their behalf.

May I suggest, when you are referring to non-metric measurements, you simply refer to them as non-metric, Imperial, or almost anything other than US-centric? In nautical matters, British mariners were mappng the world, using units such as fathoms and nautical miles, before the US existed as other than a British colony, and perhaps just an oddity discovered by Vikings or Christoper Columbus. Howard C. Berkowitz 12:41, 5 September 2007 (UTC)

I do indeed use the term 'non-metric' when referring to units that are not metric. My use of 'US centric' was not about units but about issues that you raised. Namely:

• 1. Google suggests that the term 'fathometer' is hardly used today outside North America.
• 2. I said your statement that charts do not use metres appeared to be US centric. It seems incredible to me. If you say that metric countries do not use metres for depth, I will take your word for it. Lightmouse 15:22, 5 September 2007 (UTC)

• what this proposal is trying to do is get people to make "first metric edits" ...[without]... swooping down on every single occurrence. No the proposal does not distinguish between first and subsequent edits.

I appreciate your reasoned debate. Lightmouse 10:33, 5 September 2007 (UTC)

Recent edit concerning the point about consistent decimal places

I'm transferring a discussion between Coren and me from his/her talk page.

BEFORE:

The number of decimal places should be consistent within a list or context (“The response rates were 41.0 and 47.4 percent, respectively”, not “The response rates were 41 and 47.4 percent, respectively”).

AFTER:

Outside of scientific contexts where numerical error may be significant, the number of decimal places should be consistent within a list or context (“The response rates were 41.0 and 47.4 percent, respectively”, not “The response rates were 41 and 47.4 percent, respectively”).

I don't get it. Why is scientific context at issue here? Tony 04:29, 1 September 2007 (UTC)

Because significant digits and precision count. 41 is different from 41.0— the former means "some value in [40.5 41.5[" while the latter means "some value in [40.95 41.05[. In a scientific text, changing the number of significant digits changes the meaning. — Coren ^(talk) 05:32, 1 September 2007 (UTC)

But in a list of values, we expect that they'll be of equal decimal-place precision, yes? If the list is 36.8, 51.1 and 53 and 54.5, not only does it look odd, it raises the question as to whether the writer intended 53.0 or, as you put it, somewhere in the range 52.5 ≤ x < 53.5 (in most cases, writers do mean 53.0, and even scientists have been known to be sloppy about this. I don't understand why your text exempts scientific contexts where numerical error "counts" (and where does the boundary between counting/not counting lie?). The wording needs tweaking, in any case. Tony 01:15, 2 September 2007 (UTC)

I suspect that the wording should note that scientific contexts sometimes have requirements for explicit precision that will prevent consistency, rather than implying it is the norm. SamBC(talk) 01:34, 2 September 2007 (UTC)

The previous (and changed) wording concerns only the same list or context. I'm unsure why you'd want to change the level of precision for only one item. Can we have an example of where this might be the case; otherwise, I think the change should be reverted. Tony 04:49, 2 September 2007 (UTC)

Items that happen to fall into the same list are not inherently measured to the same precision. If I measure something with a yardstick marked in inches with no finer markings, and you measure some other things with a more precise ruler, our measurements have different precision. If our measurements were listed together, in some contexts it would be undesirable to bludgeon them into the same precision. Scientists tend to be more careful about significant digits than other people are. So yes, there are edge cases where this is a legitimate issue. In general, within the context of Wikipedia, I am not sure how often this would come up. — Aluvus t/c 05:05, 2 September 2007 (UTC)

• So can we solve the issue by inserting "generally"?

The number of decimal places should generally be consistent within a list or context (“The response rates were 41.0 and 47.4 percent, respectively”, not “The response rates were 41 and 47.4 percent, respectively”).

Tony 06:30, 2 September 2007 (UTC)

• It may be worth specifying this one category of potential exceptions to help prevent wikilawyering. It may not. I've just noticed that "generally" doesn't seem to hold much weight with the wikilawyers. SamBC(talk) 08:10, 2 September 2007 (UTC)

I have trouble getting my brain around this "one category", and why one item in a list would warrant different treatment. Generally is possibly a useful way of allowing editors a little latitude (i.e., do it unless you present a good reason not to). Perhaps someon can come up with an example of this elusive 41 and 47.4. Tony 10:00, 2 September 2007 (UTC)

Can we not make the exception explicit:

Unless they were measured with unequal precision, the number of decimal places should be consistent within a list or context (“The response rates were 41.0 and 47.4 percent, respectively”, not “The response rates were 41 and 47.4 percent, respectively”).

−Woodstone 10:41, 2 September 2007 (UTC)

• Or may I rearrange the text?

The number of decimal places should be consistent within a list or context (“The response rates were 41.0 and 47.4 percent, respectively”, not “The response rates were 41 and 47.4 percent, respectively”), except in the unusual instances where the items were measured with unequal precision.

Tony 13:55, 2 September 2007 (UTC)

Split into Wikipedia:Manual of Style (dates) and Wikipedia:Manual of Style (numbers)

Resolved

 – No consensus for split.

I’ve never really understood why dates and numbers are handled on the same MoS subpage. Glancing over the discussions, it seems different people are looking after these parts and much of the archives already has been divided. I’d like to split them up into Wikipedia:Manual of Style (Dates) and Wikipedia:Manual of Style (Numbers). Has anyone serious objections? Christoph Päper 09:31, 2 September 2007 (UTC)

Or perhaps Wikipedia:Manual of Style (dates) and Wikipedia:Manual of Style (numbers), in order to more closely follow the Manual of Style in other regards? ~ Jeff Q (talk) 09:39, 2 September 2007 (UTC)

Of course, sorry. Christoph Päper 16:13, 2 September 2007 (UTC)

I have very serious objections to such a major, sudden change without consensus. Remerge them now, please, and raise it in the usual way. Tony 09:50, 2 September 2007 (UTC) Ah, I spoke too quickly. My view is that there are too many MOS submanuals and that the more there are, the harder they are to coordinate. I see expertise here nicely combined in this coverage of dates and numbers. Can you provide an example of how the division would improve things? Tony 10:04, 2 September 2007 (UTC)

I hope the maintainability would increase. This talk page tends to get rather large, but the groups discussing dates and numbers have a rather small intersection. Christoph Päper 16:13, 2 September 2007 (UTC)

Why is this page called (dates and numbers)? It is also about units of measurement, not just plain old numbers. Maybe it needs to be split into three parts instead? —Preceding unsigned comment added by 81.179.80.238 (talk) 00:12, 3 September 2007 (UTC)

And it's about a lot more than dates, which is why the section is now called "Chronological items". Tony 01:24, 3 September 2007 (UTC)

If the majority prefers so, we could of course settle on Wikipedia:Manual of Style (chronology) and Wikipedia:Manual of Style (metrology) or some such. Numbers and numbers with units are close enough, in my opinion, to be handled in one page, but dates and times only connect to these through durations (e.g. “30 s”). Christoph Päper 16:53, 3 September 2007 (UTC)

Don't like metrology (too similar to meteorology, and sounds ugly). Unconvinced that the current structure is faulty; I like the way a critical mass of experts contribute here. Tony 22:21, 3 September 2007 (UTC)

Why? Because dates are numerical, perhaps? — SMcCandlish talk cont 09:51, 19 September 2007 (UTC)

It is also about currency, which is more than mere "numbers". 81.178.90.168 (talk) 2007-09-20 00:33 UTC.

That's right, it's the "Numbers in several guises" submanual. Tony (talk) 00:50, 21 September 2007 (UTC)

Removal of metric units

Please can people comment on whether metric units are permitted in Vessel monitoring system, Fisheries management and similar circumstances? Lightmouse 10:30, 2 September 2007 (UTC)

If the editor is not directly quoting the actual treaty itself then I see no problem including the metric conversions. It helps promote understanding of the subject matter. BTW, that editor changed nautical miles to just miles, which also should be changed back but I'll let you handle that. —MJCdetroit 13:35, 2 September 2007 (UTC)

Since, as noted above, nm and knots are acceptable in SI, why convert in the first place? Knots and nautical miles are standard in shipping and aviation, because of their direct relationship to the curvature of the Earth, even to countries that use the metric system. Secondly, even if the conversion is important enough to be made, from line 198, there's no need to convert 5 nm to km twice in the span of a dozen words; the conversion hasn't changed, and it's not like anyone would forget that quickly. Sacxpert 20:00, 2 September 2007 (UTC)

I wrote the original article for vessel monitoring system, and used nautical miles when they were clearly the usage of the source material, but miles when that was the specific language of a treaty. With nautical documents, it is usually a fair assumption that nautical miles are meant. Assumptions, of course, are dangerous, and adding a conversion to kilometers, to me, adds further ambiguity to situations where a legal document is not specific.

There were a few places where a speed was mentioned, such as the 5 knot limit above which a vessel is considered unable to operate a scallop dredge. Fisheries managers monitoring this would typically either see it on a marine radar, or based on calculations from successive GPS-based reports. Nautical navigation tools customarily report in knots, and that is the convention used by mariners from thoroughly metric countries. I really believe that the metrication is gratuitous in these context.

To turn to an aeronautical example, English is the official language of air traffic control worldwide, even if it were a German aircraft talking to a Brazilian controller. Quite a number of airlines require all cockpit personnel to speak to one another in English, based on an assumption that if someone were switching languages between the cockpit and air traffic control (or other aircraft), they might make a slip and use a language that the receiver didn't understand. In other words, there are strong safety and navigational reasons for using certain traditional units, accepted by the SI oversight organization. Saying the metric conversion is needed "to make it more accessible", I believe, can further confuse a reader who otherwise will not understand the discipline's conventions. In like manner, when I write or edit pharmacology articles, I use only metric units. Howard C. Berkowitz 20:43, 2 September 2007 (UTC)

A pedantic but important point: You will hear all sorts of languages being used in aviation. English is the common language rather than the official language, although the distinction is sometimes lost on people. ICAO merely says English be made available whenever an aircraft station is unable to make use of the language spoken by the controllers on the ground. Your German pilot and Brazilian controller example is true. However, there is no ICAO regulation that forbids Spanish controllers speaking Spanish to Spanish pilots in Spain. Just thought I would point that out because we should not reinforce the already popular misconception that English communication is mandatory in the air.

Saying miles when the source says "miles" is a good thing. Attempting to be more precise than our data is a bad thing; we should not convert when it is unclear whether miles or nautical miles is meant. (It does no great harm to say "200 miles" when either could be meant, but do we convert to (320 km) or (360 km)?) Septentrionalis PMAnderson 21:03, 2 September 2007 (UTC)

As of the 8th (2005) edition of SI, the table containing both the nautical mile and the knot is now entitled "other non-SI units", replacing the titles "units temporarily accepted for use with the SI" (6th) and "other non-SI units currently accepted for use with the International System" (7th) formerly used for that table, thus they are no longer accepted for use with the SI. Instead, the 8th edition states that authors should have the freedom to use those units, but users "should always give the definition of the units they use in terms of SI units." I assume this means a statement like "1 nautical mile = 1852 m" should be included, not that the units be converted. — Joe Kress 05:45, 3 September 2007 (UTC)

You forgot to mention that they use the symbol "M" for nautical mile and "kn" for knot. That doesn't mean that we should follow their lead, IMHO. Gene Nygaard 16:44, 9 October 2007 (UTC)

Let me make a suggestion here, which perhaps will need to be linked to a Wiki article that covers both "units temporarily associated with the SI" and a category that, for want of a better term (suggestions welcome), might be called "Wiki units for ambiguous situations." The first part will cover, among other things, the nautical/aeronautical units and why they are preserved (i.e., relationship of nmi/nm to latitude, not just tradition).

A section, however, might include the term (capitalization significant) "Miles", and indicate that this is used when the term "mile", without metric equivalent and without disambiguation as to Imperial or nautical, appears in a legal document. In the latter case, the point would be made explicitly clear that since the type of miles is not known, introducing a metric equivalent could give the sense of greater accuracy than is known. A technical question here: in making a Wiki link, would something on the order of "Non-SI Units Temporarily Accepted#Miles" take the reader directly to the subsection on Miles within a larger article?

Are there any other examples besides Miles where such ambiguity exists? Tons, perhaps? —Preceding unsigned comment added by Hcberkowitz (talk • contribs) 12:17, 3 September 2007 (UTC)

I can think of a number of (commonly used) units for which ambiguity exists. Examples include calorie, gallon, gill, horsepower, kilobyte, mil, ounce, ton and quart. Thunderbird2 20:06, 9 October 2007 (UTC)

And mole. Too bad the CGPM disn't have enough sense to use the kilogram mole in the first place (for consistency with the kilogram as a base unit) and to call it a loschmidt or something named after a person. Gene Nygaard 21:17, 9 October 2007 (UTC)

The gill (Thunderbird2's link above is to wrong article) is a "commonly used unit"? Commonly used with more than one meaning? Though I have seen it a zillion times in lists of units, but I've never actually heard anybody use it to express a measurement (and most Americans, at least, would likely mispronounce it if they did), and I've seen it used once or twice in a book, maybe by Henry Fielding (1707-1754) or someone like that. Gene Nygaard 07:00, 10 October 2007 (UTC)

Well, perhaps not any more. During my mis-spent youth it was a standard measure of volume in English pubs (for spirits, not beer). As I no longer frequent these I don't know if that is still the case, so I withdraw it from the list :). Thunderbird2 08:29, 10 October 2007 (UTC)

British pubs do not use the gill anymore. It was replaced by the ml in the 1990s I think. "Make sure there are no 1/6 or 1/3 gill measures still in use in the bar as they are illegal." Lightmouse 10:58, 11 October 2007 (UTC)

There's also the cable, carat, pound and rayl, some of which are admittedly less common than others. Oh, and (though these hardly need separate mention) megabyte, gigabyte & co. Thunderbird2 11:55, 11 October 2007 (UTC)