NGS Style Manual - L -

See also Abbreviations, Plurals.

1.	Letters referred to as letters are set in italic. Plurals add an italic apostrophe plus a roman s:

the letter p plural with es

Greek letter chi his Scottish r's

 

there are two c's and two m's in accommodate

 

2.	Letters in idiomatic expressions, as nouns, and as musical notes are set in roman. Plurals add an apostrophe plus s:

S-shaped curve V-formation F-word U-turn B movies key of C minor B-flat major

ABC's p's and q's straight A's Model T's three R's X marks the spot