The RIPE NCC will create a SLURM file containing assertions with origin AS0 for all the unallocated and unassigned address space (IPv4 and IPv6) for which it is the current administrator. The file will be available for download from a well-known URL published by the RIPE NCC, so that Relying Parties (the so-called Validators) will be able to, in an automated way, fetch them and make use of them as described in RFC 8416.
Any resource holder can create AS0 (zero) ROAs for the resources they have under their account/administration. Creating a SLURM file containing similar information has the same effect on Relying Parties.
An RPKI ROA is a positive attestation that a prefix holder has authorised an Autonomous System to originate a route for this prefix to the global BGP routing table. An RPKI ROA for the same prefixes with AS0 (zero) origin shows a negative intent – indicating that the resource holder does not want the prefixes to be advertised in the global BGP routing table.
SLURM files can convey the same exact information as AS0 ROAs, thus making this distribution mechanism equivalent to having attestations in the repository. SLURM files add flexibility on the Relying Parties. A configuration directive could add or remove the processing of these files.
The RIPE NCC will update the relevant entry in the SLURM file with origin AS0 at the time of allocating address space to one of its members.