When displaying text in menus, command buttons, and tabs, use conventional book title capitalization. For example, for U.S. versions, capitalize the first letter in each word unless it is an article or preposition not occurring at the beginning or end of the name, or unless the word's conventional usage is not capitalized. For example:
Insert Object
Paste Link
Save As
Go To
Always on Top
By Name
Use this same convention for default names you provide for filenames, title bar text, or icon labels. Of course, if the user supplies a name for an object, display the name as the user specifies it, regardless of case.
Field labels, such as those used for option buttons, check boxes, text boxes, group boxes, and page tabs, should use sentence-style capitalization. For U.S. versions, this means capitalize only the first letter of the initial word and any words that are normally capitalized. For example:
Extended (XMS) memory
Working directory
Print to
Find whole words only