List of values for @render (see http://www.loc.gov/ead/tglib/att_gen.html):
altrender
bold
doublequote
bolddoublequote
bolditalic
boldsinglequote
boldsmcaps
boldunderline
italic
nonproport
singlequote
smcaps
sub
super
underline
See AR-994; the same module (and scss changes) could be applied to the Staff UI as well.
It seems that this is still (partly) a problem in the PUI in v. 2.2.2. For us, the things we've italicized seem to be appearing in italics in notes, but text we've bolded is appearing as regular text.
In some note fields in the Staff Interface (2.3.0), text within <title></title> tags is not displaying at all, such as in bibrefs and chronitems.
We'll make a separate issue for the staff interface part of this and link back to these comments.
Leaving a comment here on behalf of the Peabody Essex Museum. They have their Resource titles encoded with <emph render="bold"></emph>, which renders thusly in search results in the PUI (screenshot attached):
Verified this behavior in AS 2.8.0.