Bringhurst tells us that, as part of harmony and coutnerpoint, the typographer should set abbreviations and acronyms in small capitals. This is the style followed by many publications, including the Economist and the New Yorker.
However, in my writing, I have come across a dilemma: how to write mixed case abbreviations? This is most acute with degree names: I can easily write Master of Fine Arts as ᴍғᴀ, but how to do Doctor of Philosophy? ᴘhᴅ just looks wrong. How to handle this? I could make the ‘h’ smaller, but then the type risks being illegible. I could also just write PhD, but how can I have different rules for different degree names? I could also write ᴘʜᴅ but that implies the ‘h’ stands for something.
Similar issues arise with legal names (the European Court of Human Rights is ᴇᴄtʜʀ, with the ‘t’ looking unsightly) and many other commonly used terms. Is there a way around this, or must we abandon Bringhurst’s injunction?
Bringhurst’s advice is just advice ultimately, and that may or may not work, depending on your setup, typefaces being used, etc. If it looks good with the typeface(s) you’re using, I would use
ᴘʜᴅ without overthinking it.
European Court of Human Rights =
ECHR if you look at their wiki page.
Also, some fonts don’t even have true small caps built-in.