Bug fixes and map page banner

templates/about.html

@@ -159,13 +159,22 @@
         modify it however you like, you can claim you wrote it and charge people £1000 for a copy, I don't really mind.
         (Please don't do the last one. But if you're using my code for something cool, it would be nice to hear from
         you!)</p>
-    <h2 class="mt-4">Data Accuracy</h2>
+    <h2 id="accuracy" class="mt-4">Data Accuracy</h2>
     <p>Please note that the data coming out of Spothole is only as good as the data going in. People mis-hear and make
         typos when spotting callsigns all the time. There are also plenty of cases where Spothole's data, particularly
         location data, may be inaccurate. For example, there are POTA parks that span multiple US states, countries that
         span multiple CQ zones, portable operators with no requirement to sign /P, etc. If you are doing something where
         accuracy is important, such as contesting, you should not rely on Spothole's data to fill in any gaps in your
         log.</p>
+    <p>In the Spothole user interface, under "Your Data", you can enter your credentials for QRZ.com and/or HamQTH if
+        you have them. This allows Spothole to augment its data with lookups from these services. See the following
+        section, Privacy, for details of how these are handled. If you are looking at the map and see lots of spots in
+        the geographic centre of countries, allowing these lookups will help. For QRZ.com a paid account is required to
+        look up operator locations.</p>
+    <p>IOTA in particular causes a mapping problem, firstly that there is no official set of geodata beyond the names of
+        islands. We also have no way of telling whether priority should be given to IOTA reference or e.g. QRZ lookup,
+        for example for a G callsign in EU-005 Great Britain the QRZ home address is probably more accurate, but in
+        EU-002 Aaland islands, it's more likely a DXpedition and the IOTA would be more accurate.</p>
     <h2 id="privacy" class="mt-4">Privacy</h2>
     <p>Spothole collects no data about you on a permanent basis. All spots and alerts are "timed out" and deleted from
         the system after a set interval, which by default is one hour for spots and one week for alerts.</p>