The search tag for "format" is FM. The value "T" indicates HTML full text, and “C” indicates the format HTML Full Text with Graphics. The value “P” indicates PDF full text.
The command FM T will return only articles with HTML full text and FM P will return only articles with PDF full text.The command FM C will return only results containing HTML Full Text with Graphics. These commands may be combined with a keyword, such as "dogs and FM T".