All of these questions can be answered by consulting the NCAA D1 Manual, which can be downloaded from the NCAA website at no cost. I will, however, take a shot and say “no” to your question. A coach can contact a potential recruit about a college camp, provided the camp is open to all (with certain appropriate restrictions, like age and gender).
The starting point for the analysis is that there is no outright prohibition on coaches contacting prospective student athletes. Off-campus contacts cannot take place before August 1 of the start of the student’s junior year (end of sophomore year, beginning of junior year). Rule 13.1.1.1. Outgoing telephone calls cannot take place until June 15 at the conclusion of the student’s sophomore year. Rule 13.1.3.1. There are sport-specific exceptions. There also is a different rule for student-initiated telephone calls. So, the coach-initiated telephone call prohibition generally is for freshmen and sophomore years.
On the other hand, the rules provide that a coach may provide information about camps without regard to the contact rule, dead periods or quiet periods. Specifically, “[c]amp or clinic information may be provided at any time.” See Rule 13.4.1.9. Since this Rule doesn’t distinguish between written information and information provided by telephone, I believe that a call about a camp (with promo code) would be permissible.
Moreover, the contact limitations do not apply to camps, although there are prohibitions on offers. “Recruiting Calendar Exceptions. Generally, the interaction during sports camps and clinics between prospective student-athletes and those coaches employed by the camp or clinic is not subject to the recruiting calendar restrictions. However, an institutional staff member employed at any camp or clinic (e.g., counselor, director) is prohibited from recruiting any prospective student-athlete during the time period that the camp or clinic is conducted (from the time the prospective student-athlete reports to the camp or clinic until the conclusion of all camp activities). The prohibition against recruiting includes extending written offers of financial aid to any prospective student-athlete during the prospective student-athlete’s attendance at the camp or clinic.” Rule 13.12.1.5
Complex perhaps, but download the Manual(s) - one for each division - and work your way through your specific questions.