Many Linotype OpenType fonts that include small caps include small cap glyphs for ß fi fl and ij. In the case of ß, the glyph is two small cap s forms (SS). Same for the ligatures (FI FL IJ).

I have heard that, even if a cap ß comes into use, recommended capitalization will still be SS. For one thing, you don't want pre-existing documents to reflow! Old documents will have to be edited to have the SS replaced with the capital ß; new documents will have to physically enter the capital ß in somehow, i.e., selecting a text with an ß in it and capitalizing that text completely will probably swap that ß with SS. Don't know how the user will actually type in the capital ß yet. There is always the glyph palette…

For small caps you don't need capitalization. In OpenType fonts you have two different features to turn lowercase letters into small caps [smcp] and to turn uppercase letters into small caps [c2sc]. You may also have two different sets of small cap glyphs in a OpenType font, one to represent the lowercase as small caps, another for the uppercase.

The trouble (as I saw it) with small-caps de-ligaturization where the capital or small-caps form is not a ligature (as in ß ↔ SS, fi ↔ FI, &c.), is that the letter spacing becomes hard to adjust. I wasn't aware of the [c2sc] feature in OpenType, though; the standard Unicode capitalization routines followed by [c2sc] are what I was hoping existed. Thanks.

Some engines do it exactly the way JC describes. This is probably the most reliable approach overall.

Cheers,

T