Extended command

An extended command is executed by pressing the key followed by the command itself (the first letter or two should suffice). Extended commands exist because the developers of NetHack ran out of letters. They are supposedly less frequently used than the single-letter commands, but you probably won't get very far without using some of them.

Depending on how your game was compiled, these commands can vary or alternate keypresses may be available.

Extended commands in vanilla Nethack 3.4.3: