'match if the key is present, '
'!key to check if the key is not present, '
'key > NUMBER (like "comment_count > 12", also works with '
- '>=, <, <=, !=, =) to compare against a number, and '
- '& to require multiple matches. '
+ '>=, <, <=, !=, =) to compare against a number, '
+ 'key = \'LITERAL\' (like "uploader = \'Mike Smith\'", also works with !=) '
+ 'to match against a string literal '
+ 'and & to require multiple matches. '
'Values which are not known are excluded unless you '
'put a question mark (?) after the operator. '
'For example, to only match videos that have been liked more than '