5.517A in the Radio Frequency Table Allocation of Ireland.

Content Type
ITU FOOTNOTE
Title
5.517A
Description
The operation of earth stations in motion communicating with geostationary fixed-satellite service space stations within the frequency bands 17.7-19.7 GHz (space-to-Earth) and 27.5-29.5 GHz (Earth-to-space) shall be subject to the application of Resolution 169 (WRC-19).     (WRC-19)
Source
https://search.itu.int/history/HistoryDigitalCollectionDocLibrary/1.43.48.en.101.pdf