What I recall is that CIF/SS allows external practices and ID/Training Camps, but CIF/SD has stricter rules (based on posts from those in that area). CIF/LA section has its own so depending on where you are, its best to check with the local CIF Assistant Commissioner of your sports.
In CIF/SS, last season, my kid did a December and January ID camps and we had to clear it with his HS AD and HC, after getting an email back from the assist commish for soccer saying ok but to coordinate w/those two people.
CIF SD relaxed its rules a bit over the last few years, allowing 6v6 indoor soccer (formerly limited to 5v5) and permitting players to participate in full-sided games at college ID camps (sometimes, with prior approval, limited time and repetitions, etc, ad nauseum).