What's the technical term for groups of glyphs in an OpenType font?

Question

This question is asked with FontForge in mind, but I'm sure that if I get the terminology right then it would help me.

Here's my screenshot:

See how in this font, you can hold the mouse down and view alternates? In this case it's variants for sub and superscripts and such, but with some fonts you get three or four different takes on a character.

I'd like to work this into my font, but I don't know the technical term for what I'm looking for. I guessed Stylistic Alternate, but that's something different that shows up in the OpenType palette. Nothing else has worked yet.

Any thoughts? Like I said, if someone knows how to do this in FontForge that'd be ideal, but just an education on terms would probably help me search for answers better.

Answer 1

From Microsoft's OpenType spec (emphasis mine):

An alternate substitution identifies functionally equivalent but different looking forms of a glyph. These glyphs are often referred to as aesthetic alternatives. For example, a font might have five different glyphs for the ampersand symbol, but one would have a default glyph index in the cmap table. The client could use the default glyph or substitute any of the four alternatives (see Figure 5).

When you add a new lookup and specify Alternate Substitution, you get the following choices:

A search on one of them led me to a Wikipedia article describing OpenType and AAT features:

Access All Alternates...Used to present user with choice all alternate forms of the character

I tried it with Access All Alternates and it did what I wanted it to do!