UK radio amateurs wishing to celebrate the royal wedding can apply for a Notice of Variation to do so.
The RSGB has agreed with Ofcom an NoV to authorise the temporary use of the Regional Secondary Locator R after the United Kingdom call sign prefix.
So M1ACB could use MR1ACB, 2E1GKR could use 2R1GKR and GW1MFG could use GR1MFG—note that the celebratory letter R replaces the usual Regional Secondary Locator.
Exact details are given in the NoV documentation.
You must apply for the Notice of Variation before using the R, and it will only be valid between 19 and 21 May 2018.
To apply for the Royal Wedding Regional Secondary Locator Notice of Variation, visit the RSGB web page rsgb.org/rwrsl—the NoV is free and open to all UK licensees.