The command extension does not add any functionality directly; however, it provides the mechanism for which a majority of the existing extensions are built upon. Therefore, all custom commands follow the same basic structure and automatically have two forms and inline and block form.
Inline Command Format
!command subcommand key=value key2=value with spaces key3=value3 Some content that is optional, but if used continues until the first empty line.
Block Command Format
!command! subcommand key=value key2=value with space key3=value3 Content that is optional, but if used can include empty lines. The content ends with the "end" version of the command. !command-end!