Ledger sub-class for completeness?

[Stephen-Gates]

Wondering if it is relevant to add a Ledger / Ledger Slab / Ledger Stone sub-class for completeness?

Ledger: A rigid solid covering generally of stone lying either on top or within the monument kerbing - https://en.wikipedia.org/wiki/Ledger_stone.

I personally don't need it but given there are sub-classes like Burial Mound I thought it was worth suggesting.