ModEnc is currently in Maintenance Mode: Changes could occur at any given moment, without advance warning.
UIName
Generally the first flag on an object, The content of it is interpreted as being the name of a string in ra2(md).csf. That string should contain the name of the object the flag belongs to.
Example
[E1] UIName=Name:E1
Meaning: If the game is in any situation asked to output the name of the unit "E1", it will respond with whatever is put in Name:E1 in ra2(md).csf - "GI", in this case.
Seems to have no effect when used in the [ General ] section of the rules.