There are four GPS signal specifications designed for civilian use. In order of date of introduction, these are: L1 C/A, L2C, L5 and L1C. L1 C/A is also called the "legacy signal" and is broadcast by all currently operational satellites. L2C, L5 and L1C are "modernized signals," are only broadcast by newer satellites (or not yet at all), and , none are yet considered to be fully operational for civilian use. In addition, there are "restricted signals" with published frequencies and chip rates but encrypted coding intended to be used only by authorized parties. Some limited use of restricted signals can still be made by civilians without decryption; this is called "codeless" and "semi-codeless" access, and is officially supported.