add new tag for license type

[Jilayne Lovejoy]

consider adding a tag that goes at license level for type of license. Along the lines of:

permissive or non-reciprocal
weak copyleft or file-level copyleft or file-scoped reciprocal
copyleft or project-level copyleft or project-scoped reciprocal

[Jilayne Lovejoy]

some further thoughts on types, specifically "weak copyleft":

I prefer permissive and copyleft to describe the types. To me, "reciprocal" is not accurate because most of the conditions only flow downstream.

is it useful to include a "weak" or "intermediate" copyleft category for licenses like MPL? And if so, do any versions of LGPL belong in that category?

I do think the "weak" category is useful, though I have heard some people (of quite different viewpoints BTW) say it is misleading, or useless. Some people may have a different compliance process for these licenses. For example, white listing these licenses if the code is not modified. That's a ham-handed rule, but it's very difficult to violate weak copyleft licenses if you don't modify the code, and particularly its interface.

I would put LGPL in the same category. Although the rules for LGPL are different from, say, MPL, it's not terribly useful to put it in either its own category (moderately weak?) or with GPL.

Some people have called this category by different names, such as library licenses or file-based licenses. But I think weak copyleft is descriptive as well as widely understood.