System Generation and Display - acronyms and Symbols

[Kaiser (OP)]

Could not find any answer to this, I guess it is linked to the survey system.

What does M1 or M2 next to the planet name stand for in the system generation and display?

Sometime I find just a number "1" or "4". What do they stand for?

What "OM Eligible" means?

[SpaceMarine]

M = minerals have been found on the planet

M1-M5 = their is potential for ground survey of low - Excellent and there are minerals

OM Eligible means the body is small enough to be orbitally mined

[Kaiser (OP)]

M = minerals have been found on the planet

M1-M5 = their is potential for ground survey of low - Excellent

OM Eligible means the body is small enough to be orbitally mined

Thank you SpaceMarine, what about the only number? (see the screenshot attached in the first post)

[SpaceMarine]

It means there are no minerals but ground survey potential