diff -r d4b67dc6f4eb -r 90f4df1970b8 .hgtags
--- a/.hgtags	Sun Dec 27 15:15:37 2020 +0100
+++ b/.hgtags	Sun Dec 27 15:55:42 2020 +0100
@@ -38,3 +38,4 @@
 83774d669b5181fb28d19d7a0219fbf6c6d38aab Isabelle2019
 abf3e80bd815c2c062b02c78b256f7ba27481380 Isabelle2020
 21ff9c1a464494b3a61c3538650664cc1b42c0cb Isabelle2021-RC0
+d4b67dc6f4ebd5f0fbd4ed1cccd0cc32c344d122 Isabelle2021-RC1