Aren’t “rules and regulations” written by people under direction of a president, such that it is effectively the president’s work? Do they just stand on their o

Aren’t “rules and regulations” written by people under direction of a president, such that it is effectively the president’s work? Do they just stand on their own with no legal backing? Or do they want the president to be the one actually writing them all? Or is it his signature they want? Undoing them isn’t just the same as undoing previous presidents’ work?