Taking this clause back out per concerns on the Acceptible Exceptions proposal: I don’t think we should allow a proposal to amend core on the grounds that the text is replacing only appears once, since that can happen inadvertently. Voters should know for sure whether the proposal they’re reading and voting on is amending Core.

If this clause is left in, a malicious player could bury an innocuous-looking “change X to Y” in the middle of a long and boring proposal, which reads as if it’s changing whatever dynastic rule it’s talking about, then reveal after voting that it actually made some devastating modification to core.

Alternatively, and more likely, a careless player could overwrite a core rule simply by misquoting a dynastic one, or by casually proposing to “change X to Y” on a dynastic sentence without neither proposer nor voters checking whether that also appears in core, and being stuck when a proposal further up the queue removes that dynastic sentence, leaving a core one in the crosshairs. (Only a few days ago, we voted something through with nobody even noticing that the word it was replacing appeared twice in the sentence it was talking about.)