The documentation is about the comment my problem is about the content.
But yes, it is not a bug, it is expected.
Not because it's in the documentation (it's not) but because @Slava (who I guess is from the dev team) say so.
But thank you anyway for your contribution.
But the meaning of the doc explanation is for both string comment and variable by their values content,
the comment which will be as #strict literal,and the variable will be without #strict literal,it means their value content should be lesser than 63characters too.