Many times. Asking that question tells me you have no idea what the Guidelines are, the enforceability by the Board of Directors, etc. I suspect 80% or so of thousands of issued CPI violations could be based on the Guidelines ... and they must be covered by the DRs. 

Any entity writing enforceable laws or rules or whatever you choose to call them can change those at any time. When changed, the new rules apply. The current Guidelines were passed by the OPA Board of Directors in April 2024. They are in effect, and enforceable, your puzzling comment above notwithstanding

What is it any thinking person does not understand about that. Rules/laws/etc are constantly changing. Doesn't make them unenforceable.

Section 600.2 General Criteria G. Number says: "In addition to the address plate, only one (1) sign of any type shall be permitted on any numbered lot." 

Is that sentence confusing?