diff --git a/templates/cavewallets.html b/templates/cavewallets.html
index 9ad907f9f..771083b88 100644
--- a/templates/cavewallets.html
+++ b/templates/cavewallets.html
@@ -23,7 +23,8 @@ traced to produce Tunnel or Therion drawings and eventually the final complete c
 {% include 'wallet_table.html' %}
 <p>Note that names in italics are copied from the related survex file block name.
 <br />
-<p>Total underground survey length: {{length_ug|floatformat:"1g"}} m
+<p>Total underground survey length: {{length_ug|floatformat:"1g"}} m<br />
+Note that this is for <em>all the wallets</em> listed above, which includes those which may not be directly relevant to what you are looking for.
 <br />
 <table width=95%>
 <tr><th>Wallet</th><th width=13%>Wallet Date</th><th>Wallet Name</th><th width=25%>People</th><th>Scans</th><th>Survex blocks</th><th>Drawings using these scans</th></tr>