In general, access to data that is public (to whatever extent), is best mediated by some system. E.g. it's not considered ideal to provide a login to a database system for everyone, even if the visible data is (in theory) quite limited. Doing so would leave it more open to attack than is necessary.
So, to provide access to the data for the mediating system, we need an account/userid to control access. The recent (2014-08) direction is to use the userid "cscf-dat" ("cscf-data") to control access to files that contain database passwords. We can also expect to see that as a database userid, with which to associate access restrictions.
There can be variants, depending upon the security and source of the data. E.g. we have userid "cscf-ona" which controls access to a password for access to part of the ONA (campus network) data.
An example of "cscf-dat" usage is the CSCF Points of Contact data.