Emblem of Minas Morgul

[Valandil]

As seen by Samwise Gamgee, at the beginning of Book VI of LOTR, the livery of Minas Morgul was:

"...a Moon disfigured with a ghastly face of death..."

It has only just occured to me - that Minas Morgul - which used to be Minas Ithil - the Tower of the (Rising) Moon - makes use of a Moon in its emblem, and that's what the previous name of the Tower signified.

So - rather than simply discard the old symbols, they (the new management = the Nazgul) might possibly have just modified them.