There are five general types of cover letters:
1. Application Letter - to apply for a specific job opening
2. Referral Cover Letter - mentions the name of a person who has referred you to a job
3. Letter of Interest - a prospecting letter, inquires about possible job openings
4. Networking Letter- request job search advice and assistance (sample networking letters)
5. Value Proposition Letter - a brief statement explaining what makes the candidate unique
If you are to request assistance and support from a job network, therefore, you must use the networking letter type of cover letter.