\eqref in italic math environnment
There is what I think is a very good explanation of this is the mathtools
manual in paragraph 3.2.2, where they discuss the \refeq
command introduced by mathtools
. They explain that \refeq
, just like \eqref
, uses upright font even in the middle of italics text to "avoid what
could possibly lead to confusion in cases where the tag font has very different form in upright and italic shape".
They give an example where they use "Q&A" as a tag while the font is set to Palatino. Apparently in Palatino, the character &
looks very different in italics than in upright, so the reference in italics would look very different from the actual tag, which is upright.