Per https://pypi.org/project/rfclint/, the actions performed are:
The following is a description of how the selection is done for what is spellchecked. The first thing to note is that this list contains v2 (RFC 7749) as well as v3 (RFC 7991) vocabulary.
Elements that are checked:
annotation, area, artwork, blockquote, city, cref, code, country, dd, dt, email, keyword, li, name, organization, phone, postalLine, refcontent, region, sourcecode, street, t, td, th, title, uri, workgroup
Attributes that are checked:
'title': ['ascii', 'abbrev'], 'seriesInfo': ['name', 'asciiName', 'value', 'asciiValue'], 'author': ['asciiFullname', 'asciiInitials', 'asciiSurname', 'fullname', 'surname', 'initials'], 'city': ['ascii'], 'code': ['ascii'], 'country': ['ascii'], 'region': ['ascii'], 'street': ['ascii'], 'blockquote': ['quotedFrom'], 'iref': ['item', 'subitem'],
where the first item is the element name and then the list of attributes that would be checked.