In the case of RL issues and having to leave right away, an effort should be made to leave the system before logging out. If that isn't possible, an OOC message in system chat should be necessary.
Edit: In addition, in order to prevent abuse during RP combat, logging out in such a way should be considered a "death" under the 3 death rule.
Regarding system chat:
Quote:3.3 All messages in chat must be in understandable English, unless the chat is private and both members know the language being used.
3.4 Out-of-character (OOC) chat should not be used for system chat. Using out-of character in roleplaying chat should be marked with "OOC".