Most of the time, GET should not affect system state at all (other than caching, etc). Idempotent can still have effects on the first access. Even deletion can

Most of the time, GET should not affect system state at all (other than caching, etc). Idempotent can still have effects on the first access. Even deletion can be idempotent. I generally see PUT and PATCH classified as idempotent (for the same input).