Just wanted to share the Editorial Team's preferred format approach when it comes to variants...
For the Item Description Field:
if its a general variant cover it would be formatted like so: Variant Cover by Joe Smith
If its a lettered variant it be: Cover A by Joe Smith
If the variant is from a special source like a comic shop or convention it would be like so: Red Star Comics Variant Cover by Joe Smith
later printing variants (which apparently is thing these days) would be like so: 2nd Printing Variant Cover by Joe Smith
If you know the ratios like its a 1 in 25 variant, it would be like so: 1:25 Variant Cover by Joe Smith
For the notes field:
there's no need to repeat any of item description variant details in the notes field.
If the variant has a limited run, a note like so can be included: Limited to 1,000 (limited number can be also be noted in the circulation field)
if it includes a certificate of authenticity, a note like so can be included: Includes Certificate of Authenticity
I'll share more as the Editorial team thinks of them but those are the most common variant types that we tend to see these days.