20mm Cartridges with a Black Band

I have two cartridges with a black band above the driving band.
20x139 Practice by RH. Projectile marked: MUN LOS RH-01 -X.
20x110 Navy looks like HE-T. No marks on the projectile. Real fuze with no internals.
What are these loadings and what does the black band mean ?

I don’t know what the black band means.

The 20x110USN has the appearance of a fairly standard HE-I (there is no HE-T for this cartridge) less the black band. The fuze should be capped, this looks like a repainted TP projectile,

Could be the band denotes INERT/INERTED?.

These came as 10 rounds linked together with cardboard tubes covering the projectiles only.
So it was an inert belt of cartridges.

The 20x139 is factory internal by Rheinmetall. The meaning is only known there and most likely only by the people wo arranged for this marking back in the time.

Please never expect that a color marking in one country has the same meaning in another one.