[word=string] [word=□] □ □
[word=string] [word=is] □ □
[word=string] [word=given] □ □
If a non-empty string is given , it will be placed in the contents of the About this document ... If at least one string is given , nothing will be printed but the return status will be zero if all strings are names of existing widgets ( or of user-defined widgets if the - a flag is not given ) and non-zero if at least one string is not a name of an defined widget . If no string is given , the default label ( numerical ) is used .