<SID>
The string <SID> can be used in a mapping or menu.
When executing the map command, Vim will replace <SID> with the special key code <SNR>, followed by a number that’s ...
Remenber to use :h <arg> for help
Ref: https://learnvimscriptthehardway.stevelosh.com/
BasicEcho
:echo "hello"
:echom "hello"
区别在于echom会将消息放入消息队列中:messages
Setting option...