Is there a correct abbreviation or specific way to identify in writing a joint/combined manual and automated fire alarm system.

For example ML3 or L5N?

Thank you

The following category combinations exist:

M - Manual (Call points & sounders). 

L5 - Life Risk specific detection (no call points, sometimes no sounders)

L5/M - Life Risk specific detection (with call points and sounders)

L4 - Escape route detection

L3 - As L4 plus rooms opening onto escape routes

L2 - As L3 plus risk specific additional areas

L1 - Everywhere (almost!)

L1 to L4 do not require the /M suffix as they MUST always include call points and sounders

P2 - Property risk specific detection (must be monitored, longer standby times, no call points, may have no or limited sounders)

P1 - Property protection detection everywhere (almost - also must be monitored, longer standby times, no call points, may have no or limited sounders)

P2/M & P1/M Property protection systems also incorporating call points and sounders to meet the minimum life safety requirements

You can also mix P & L systems such as P2/L4 which would be a building with manual call points and sounders, escape route detection for life safety and then some additional detection for a property protection purpose along with remote monitoring.