ne's manual

4.12.5: Help

the long version are accepted). If no argument is given, a list of all existing commands in long form is displayed, allowing you to choose one. You can browse the help text with the standard navigation keys. If you press RETURN, the command list will be displayed again. If you press F1 or ESCAPE, you will return to normal editing.

This command is never registered while recording a macro, so that you can safely access the help system while recording. See Record.