Similar to Haven teleports, but for missions. Teleporting to a mission would take you its mission lobby.

We could have abbreviations specific to each of the bosses, prestige (if available, including events), and expansion (if unlocked) missions:
/mission fsc (The King of Ashes)
/mission c42 (Compound 42)
/mission mott (March of the Tortodrones)
/mission och3 (Operation Crimson Hammer, Tier 3)

More abbreviations can be found here under the "Locations, Missions, and Bosses" section:
https://wiki.spiralknights.com/List_of_commonly_used_abbreviations

A general command for other missions:
/mission [rank] [position on list]
/mission 9-3 2 would take you to the mission lobby of The King of Ashes mission (if unlocked), since it is 2nd on the list of 9-3 missions.

Can use a similar format for an arcade command:
/gate [gate number] [tier]
Doing /gate 4 2 would take you to the fourth gate in rotation, starting from the second tier lobby, Moorcroft Manor, if unlocked.