diff --git a/cave_data/cavealiases.txt b/cave_data/cavealiases.txt
index 87fc23ee7..e498250b5 100644
--- a/cave_data/cavealiases.txt
+++ b/cave_data/cavealiases.txt
@@ -1,19 +1,23 @@
 ; This is the list of cave aliases which is parsed when a database reset is done.
-
-; This is IMPORTANT as it enables old logbook cave ids to be redirected to current cave ids.
-; such as "2017_cucc_28" => "1623-290" is Fishface.
-
-; The format is ("<identifier>","<identifier>")
-; e.g.
-("2017_cucc_28", "1623-290")
- 
-
-; lines with initial semi-colon ; or hash # are comments
-; extra commas are ignored
-; extra blanks are ignored
 ; This capability created in July 2024.
 
-# various funnies to cope with cave names used in logbooks
+; This is IMPORTANT as it enables old logbook and wallet cave ids to be redirected to current cave ids.
+; such as "2017_cucc_28" => "1623-290" is Fishface.
+
+; The format is ("<alias identifier>","<target identifier>")
+; e.g.
+("2017_cucc_28", "1623-290")
+("2012-0w-01",   "2012-ow-01") # catch the typo: zero for 'O'
+
+; target identifiers must be all in lower case
+
+; lines with initial semi-colon ; and anything after hash # are comments
+; extra commas are ignored
+; extra blanks are ignored
+; later aliases can reference earlier ones
+; all upper- and lower-case variants are done automatically
+
+; various funnies to cope with cave names as found in logbooks
         ("kh", "1623-161"),
         ("161-kh", "1623-161"),
         ("204-steinBH", "1623-204"),
@@ -28,4 +32,5 @@
         ("fishface", "1623-290"),
         ("gsh", "1623-291"),
         ("1623-2023-lc-01", "1623-318"),
-        ("tempest", "1623-2023-lc-01"),
+        ("tempest", "1623-2023-lc-01"), # note re-use of alias from previous line
+