diff --git a/lineage_notes.txt b/lineage_notes.txt
index 493b54ae..a3581301 100644
--- a/lineage_notes.txt
+++ b/lineage_notes.txt
@@ -876,6 +876,7 @@ CH.1.1.9	Alias of B.1.1.529.2.75.3.4.1.1.1.1.9, England, defined by S:I1232V
 CH.1.1.10	Alias of B.1.1.529.2.75.3.4.1.1.1.1.10, Ireland, ORF1a:G442S
 CH.1.1.11	Alias of B.1.1.529.2.75.3.4.1.1.1.1.11, ORF1a:A1176T
 CH.1.1.12	Alias of B.1.1.529.2.75.3.4.1.1.1.1.12, S:L858I on ORF1a:A486V branch, Denmark
+FS.1	Alias of B.1.1.529.2.75.3.4.1.1.1.1.12.1, found mainly in Denmark, from pango-designation issue #1816
 CH.1.1.13	Alias of B.1.1.529.2.75.3.4.1.1.1.1.13, ORF3a:S171L
 CH.1.1.14	Alias of B.1.1.529.2.75.3.4.1.1.1.1.14, N:T362I
 CH.1.1.15	Alias of B.1.1.529.2.75.3.4.1.1.1.1.15, found mainly in Lithuania, Germany and UK, from pango-designation issue #1726
diff --git a/pango_designation/alias_key.json b/pango_designation/alias_key.json
index eddf9a45..25abc240 100644
--- a/pango_designation/alias_key.json
+++ b/pango_designation/alias_key.json
@@ -147,6 +147,7 @@
     "FP": "XBB.1.11.1",
     "FQ": "B.1.1.529.5.3.1.1.1.1.1.1.39",
     "FR": "B.1.1.529.2.75.5.1.2.3",
+    "FS": "B.1.1.529.2.75.3.4.1.1.1.1.12",
     "XA": ["B.1.1.7","B.1.177"],
     "XB": ["B.1.634","B.1.631"],
     "XC": ["AY.29","B.1.1.7"],