I assume that you're seeing these in URL query parameters.
Adobe Analytics doesn't dictate the query parameter to use for campaign tracking, both external (e.g. from paid search, social media, email, etc) nor internal (e.g. homepage banners, product promotions, etc). So organisations come up with their own query parameters to identify their campaign tracking codes.
"cid" is commonly used with external campaign tracking codes. You might also see "cmp" or even "campaign".
"icmp" is commonly used with internal campaign tracking codes (where the "i" stands for "internal"). You might also see "icid", maybe "icampaign", though I haven't seen the latter myself.
This should be documented with the organisation's Adobe Analytics implementation guide or Solution Design Reference (SDR). The marketing folks who prepare campaign URLs should also know about these query parameters.
