API/A vs CR/C: Understanding ITU Satellite Notification Types

A satellite network doesn't appear once in ITU records — it moves through several distinct filing stages, each with its own acronym, its own legal weight, and its own role in the coordination process. Mixing them up is an easy mistake to make and an easy one to avoid once the sequence is clear.

The general sequence

Most satellite networks move through ITU filings roughly in this order, though not every network uses every stage, and the exact path depends on the frequency bands and services involved:

Stage	What it is
API/A Advance Publication Information	An early-stage filing that puts an administration's intent to use a satellite network on the record. It's published so other administrations get advance notice, well before detailed coordination begins. It carries less legal weight than a coordination or notification filing, but it's often the first time a new network becomes visible at all — which makes it worth screening against, not just the later, more formal stages.
CR/C Coordination Request	A formal filing in which an administration publishes its planned use of a satellite network in enough technical detail that other administrations can assess whether coordination is needed under the ITU Radio Regulations. This is where the process starts to have real procedural consequences — other administrations have defined opportunities to respond.
CR/D Coordination Report	Published once coordination under a CR/C has progressed, listing the finalized coordination requirements — including any special sections or provisions agreed with affected administrations.
Notification	The filing submitted for actual entry into the Master International Frequency Register once the network is brought into use. This is the stage that, if accepted, gives the assignment recognized international protection.

Why the distinction matters for screening

Each notice type represents a different level of commitment and a different coordination status. A frequency overlap with an API/A filing is a heads-up — the network may still change substantially before coordination. An overlap with a CR/C is a much more concrete signal that you may have an actual coordination obligation. Treating every overlapping filing the same way, regardless of notice type, makes it harder to prioritize which ones need a phone call this week versus which ones are worth a note to revisit later.

A practical implication

Because API/A filings appear earliest, they're also the most useful ones to monitor continuously if you want early warning — by the time a conflicting network reaches CR/C, both sides typically already know coordination is on the table. Catching the overlap at the API/A stage buys time to plan before that conversation becomes urgent.