Category talk:Plasma processing

Metalworking sub-cat

Not all plasma processes are intrinsically used in metalworking. For instance, look at Plasma polymerization, which is used to polymerize monomer liquids and solids. Also, Plasma ashing usually involves fluorine or oxygen gases. As such, I don't feel that this category ought to be a sub-cat of category:metalworking. Wizard191 (talk) 23:19, 10 August 2009 (UTC)[reply]

Whilst what you say is true, most industrial plasma processes are used as a form of metalworking. The same could be said of turning or press operations, not all of those are metalworking either, but we have no hesitation in listing them under metalworking.

Categories with MediaWiki are somewhat restricted in their expressiveness. They can't express a rigid and absolutely containing hierarchy, and it's wrong for us to pretend that's what they are doing. Instead we should use them if there's a strong and relevant inclusion (rather than containment) from one to the other: which we surely have for plasma processes and metals. Andy Dingley (talk) 23:54, 10 August 2009 (UTC)[reply]

Alright, you convinced me. I'll let it stand. Wizard191 (talk) 00:01, 11 August 2009 (UTC)[reply]