These are the sa-mp commands from SA:MP which you can find in all servers:

/q - Close the SA:MP client
.
/quit - Close the SA:MP client (same as above).

/save [extra] - Save your current coordinates into savedpositions.txt

/interior - Shows the current interior ID.

/fpslimit [20-90] - Set the maximum FPS for your client.

/pagesize [10-20] - Change the amount of lines in the chatbox.

/timestamp - Show time stamping in the chatbox.

/headmove - Toggle player's head movements.

/dl - Handy developers command to show vehicle information.

/mem - Shows the current amount of memory usage.

/rs - Saves On-Foot coordinates in rawpositions.txt

/cmpstat - Exists but doesn't seems to do anything? more info please!

/audiomsg - If this option is set to 0, no Audio Stream: messages will be displayed in the chat
window when the server requests the client to connect to an audio stream.

/fontsize - Editing the font page on chat.