:help si<CTL-D> (type :help space s i and control-d after the i) will give you all available variations in help on si, including 'si' and si among many others.

:help si<CTL-D> (type :help space s i and control-d after the i) will give you all available variations in help on si, including 'si' and si among many others. CTL-D is a sort of intelli-suggest in context (except it's move 1/2 page down in command mode) :help<CTL-D> gives variations of help in your installation. :help <CTL-D> (help then space then control-D) gives more variations. :help help<CTL-D> (ask for help on help, with a control-D immediately after the last p) gives more variations on help. :help c_CTRL-D (literally typed just like that) is the help entry for using CTL-D on the command line. :help CTRL-D<CTL-D> (everything up to the first D literally, then control-D) lists all the different help subjects for CTRL-D in various contexts. :<CTL-D> (control-D immediately after typing colon) lists all the things you can do on the command line, including help. Help.