I was wondering about those six-letter Mexican call signs. Unusual in North America where the U.S. has only three and four-letter call signs. Canada also has mostly three and four-letter call signs. But there are a few five-letter call signs for some CBC television stations, mostly French stations in English communities and English stations in French communities. (For instance, CBU is the English-language CBC Radio One station in Vancouver. CBUT is the English-language CBC television station. And CBUFT is the French-language television station.)
So in Mexico, it's...
X for meXico
H for FM or TV station
CS for concesión social = social concession
Then two more letters for the station's actual designation
I assume "concesión social" means a non-commercial station owned by a non-profit organization.
Pretty much. With some early exceptions (the PB and PE series, plus the IFT-4 auction), the series are now
CC - Concesión Comercial. Two sequential letters (in FM, with a gap after CY and before FC, sequential as in lot number in the auction) or related to station location (in AM). (IFT-8 auction only) The assignment method means that in nearly every case, stations in the same city from IFT-8 are adjacent call signs—XHCCCB-FM or XHCCCC-FM in Culiacán, for instance.
CP - Concesión Pública. Two sequential letters (in FM and TDT, television) or related to station location (in AM).
CS - Concesión Social. Two sequential letters.
SC - Social Comunitaria. Community stations. Assignments are vaguely sequential but not quite.
SI - Social Indígena. Indigenous stations, which are generally owned by indigenous communities.
In the CP and CS series, these call signs are assigned at time of allotment, not time of award to an applicant. The reason is that only a fixed number of public and social stations are made available each year for specific areas in specific filing windows, while community and indigenous applications can be taken on any open business day and for communities not already listed in a filing window.
Your definition of social concession is pretty much correct. Social stations are noncommercial and generally are owned by individuals, civil (read: non-profit) associations, and private educational institutions. Public stations are only owned by governmental institutions at all levels, including public universities and other educational institutions.
Community and indigenous stations are subtypes of social station that, in exchange for certain requirements on the concessionaire, qualify for some extra perks. The biggest is that there is a reserved band for them, 106–108 MHz and the AM expanded band (which each have some grandfathered stations that could not be repacked below 106). The other is that government agencies are required to allocate one percent of their annual marketing budget to these stations (as a whole), though compliance is low.
You can change your call sign, but not a lot of people do in Mexico.
