I suspect the real reason for using these key combinations is that they are original vi commands as developed by Bill Joy in the late 70s. Most likely, his keyb

I suspect the real reason for using these key combinations is that they are original vi commands as developed by Bill Joy in the late 70s. Most likely, his keyboard didn't have PgUp or PgDown keys. The same commands also work with the `less` pager -- and they're specified in POSIX for the `more` pager: http://pubs.opengroup.org/onlinepubs/9699919799/utilities/more.html http://pubs.opengroup.org/onlinepubs/9699919799/utilities/mo...