Depending on the rules of mobile equipment registration in a country the CEIR database may contain other lists or fields beside IMEI.
Originally abbreviation CEIR stood for IMEI Database, created and provided by GSM Association.
Thus, it turns out that a stolen phone, once blacklisted by the GSMA CEIR, cannot be used on a large number of cellular networks, which means that the theft of mobile devices will become meaningless.
It became clear that the blocking of stolen devices should be introduced simultaneously in all mobile networks of the country by legislative measures at the initiative of the communications regulator.
[3] A system that directly blocks the registration of a mobile device on a cellular network – EIR.
Each MNO must have at least one EIR, to which IMEI check requests (CheckIMEI) are sent when registering a device on the network.
Such system may be established at mobile network even it doesn’t use black list and there are no CEIR in a country.