diff --git a/roles/0-init/tasks/validate_vars.yml b/roles/0-init/tasks/validate_vars.yml
index 5c79cc537..bded743e7 100644
--- a/roles/0-init/tasks/validate_vars.yml
+++ b/roles/0-init/tasks/validate_vars.yml
@@ -36,6 +36,11 @@
 # 2020-07-08 - Excellent analysis & summary by Jon Spriggs: "In Ansible,
 # determine the type of a value, and casting those values to other types"
 # https://jon.sprig.gs/blog/post/1801
+#
+# 2021-01-29 - ansible-base 2.10.5 (1) is more strict about empty string vars
+# (2) no longer supports "when: myvar is boolean", "is integer" & "is float"
+# (3) brings yet more "Ansible collection" dependency changes (undocumented!)
+# Details: https://github.com/iiab/iiab/pull/2672 (see also #2669)
 
 # 3. "How do i fail a task in Ansible if the variable contains a boolean value?
 # I want to perform input validation for Ansible playbooks"