The '''apostrophe''' allows explanatory comments, or remarks, to be inserted in a program. These may be included anywhere in the source code and extend to the end of the line. Comments are ignored when the program is run.
* [[REM]] can also be used to insert comments but may only be used as the last, or only, statement on a line.
* QBasic [[metacommand]]s like [[$INCLUDE]] must be included in a comment using either [[REM]] or [[apostrophe|']].
* [[Apostrophe]] comments, unavailable in earlier dialects of the BASIC language, are now generally favored over [[REM]] statements for their greater flexibility.
* Comments are also useful for disabling code for program testing and debugging purposes.