The ITU revisions actually in force
A link budget is only as current as the recommendation it cites. Three of the documents this field leans on hardest were revised recently enough that a citation written in good faith two years ago now names a superseded edition.
What changed
ITU-R P.837 is now at revision 8, approved September 2025. P.837 is the rainfall-rate recommendation — the one that feeds rain attenuation at every frequency where rain matters. The previous revision, P.837-7, dates from June 2017 and is marked superseded on the ITU's own page.
ITU-R P.525 is now at revision 5, approved November 2024, replacing P.525-4 from August 2019. This is free-space path loss. The formula is not going to surprise anyone, but the document that carries it has moved.
The Radio Regulations are at the Edition of 2024, incorporating the Final Acts of WRC-23 and superseding the Edition of 2020. WRC-23 also adopted Resolution 775, which concerns power-flux-density and e.i.r.p. limits for inclusion in Article 21 at 71–76 and 81–86 GHz.
Why it matters more than a version number
For P.525 the substance almost certainly did not move. For P.837 it might have: the underlying rainfall dataset is the whole content of the recommendation, and a revision after eight years is not usually editorial.
The Radio Regulations case is different again, and it is the one worth care. An edition change to the Radio Regulations is not a citation-hygiene problem — it is a change to what is permitted. If your product screens a transmission against an Article 21 limit, the table you implemented and the table now in force are two different objects until someone reads Volume 1 of the 2024 edition and confirms otherwise. We treat the edition string as confirmed stale and the numeric limits as unverified until that reading happens, and we would suggest anyone else in the same position does the same.
We re-pinned all three.
Where to read it
- ITU-R P.837: https://www.itu.int/rec/R-REC-P.837/en
- ITU-R P.525: https://www.itu.int/rec/R-REC-P.525/en
- Radio Regulations: https://www.itu.int/pub/R-REG-RR
Checked the same day and unchanged: P.676-13, P.618-14, P.838-3, P.839-4, ICNIRP's 2020 RF guidelines, and IEEE Std C95.1-2019.