New header METAs proposal

[Roland Melkert]

There are also several parts that lack a category even if similar parts have a category.

If no category is given the first word (excluding ~, _, =) of the description is used as the category.

How and where do software actually use the category? AFAIK LeoCAD uses a query and Stud.io use their own grouping.

bin sorting (e.g. through filtering like in my LDCad's pbg files).