diff --git a/core/constants.py b/core/constants.py
index ae8a00a..d114a22 100644
--- a/core/constants.py
+++ b/core/constants.py
@@ -89,3 +89,17 @@ UNKNOWN_BAND = Band(name="Unknown", start_freq=0, end_freq=0)
 
 # Continents
 CONTINENTS = ["EU", "NA", "SA", "AS", "AF", "OC", "AN"]
+
+# Propagation modes used in VHF/UHF DX cluster comments, e.g. "JN61ES<ES>JM56XT". I don't think there's an official list
+# of these anywhere, but here are some I've seen or seen reference to
+PROPAGATION_MODES = {
+    "F2": "F2 layer ionospheric",
+    "ES": "Sporadic-E",
+    "TR": "Tropospheric ducting",
+    "TEP": "Trans-Equatorial Propagation",
+    "EME": "Earth-Moon-Earth",
+    "AU": "Aurora",
+    "MS": "Meteor scatter",
+    "RS": "Rain scatter",
+    "AS": "Aircraft scatter"
+}
diff --git a/data/spot.py b/data/spot.py
index ed2ad1f..6da7007 100644
--- a/data/spot.py
+++ b/data/spot.py
@@ -10,7 +10,7 @@ import pytz
 from pyhamtools.locator import locator_to_latlong, latlong_to_locator
 
 from core.config import MAX_SPOT_AGE
-from core.constants import MODE_ALIASES
+from core.constants import MODE_ALIASES, PROPAGATION_MODES
 from core.geo_utils import lat_lon_to_cq_zone, lat_lon_to_itu_zone
 from core.lookup_helper import lookup_helper, infer_band_from_freq, infer_mode_from_comment, \
     infer_mode_from_frequency, infer_mode_type_from_mode
@@ -99,6 +99,8 @@ class Spot:
     freq: float | None = None
     # Band, defined by the frequency, e.g. "40m" or "70cm"
     band: str | None = None
+    # Propagation mode, if known
+    propagation_mode: str | None = None
     # Comment left by the spotter, if any
     comment: str | None = None
     # QRT state. Some APIs return spots marked as QRT. Otherwise we can check the comments.
@@ -288,19 +290,30 @@ class Spot:
         if self.sig_refs and len(self.sig_refs) > 0 and not self.sig:
             self.sig = self.sig_refs[0].sig
 
-        # Parse "de_grid<mode>dx_grid" structures from the comment, e.g. "JN61ES<ES>JM56XT" or "JO02GQ<>KN17LG". These
-        # are common on cluster spots and can provide grid references in preference to e.g. QRZ lookup.
+        # Parse "de_grid<prop_mode>dx_grid" structures from the comment, e.g. "JN61ES<ES>JM56XT" or "JO02GQ<>KN17LG".
+        # These are common on cluster spots and can provide grid references in preference to e.g. QRZ lookup, as well as
+        # being the only source we have for propagation mode.
         if self.comment:
-            grid_pair_match = re.search(
-                r'\b([A-Ra-r]{2}\d{2}(?:[A-Xa-x]{2}(?:\d{2})?)?)<[^>]*>([A-Ra-r]{2}\d{2}(?:[A-Xa-x]{2}(?:\d{2})?)?)\b',
+            grid_mode_grid_match = re.search(
+                r'\b([A-Ra-r]{2}\d{2}(?:[A-Xa-x]{2}(?:\d{2})?)?)<([^>]*)>([A-Ra-r]{2}\d{2}(?:[A-Xa-x]{2}(?:\d{2})?)?)\b',
                 self.comment)
-            if grid_pair_match:
+            if grid_mode_grid_match:
+                # regex matches, so extract grids:
                 if not self.de_grid:
-                    self.de_grid = grid_pair_match.group(1).upper()
+                    self.de_grid = grid_mode_grid_match.group(1).upper()
                 if not self.dx_grid:
-                    self.dx_grid = grid_pair_match.group(2).upper()
+                    self.dx_grid = grid_mode_grid_match.group(3).upper()
                     self.dx_location_source = "SPOT"
 
+                # And extract propagation mode:
+                mode_tag = grid_mode_grid_match.group(2).upper()
+                if mode_tag and not self.propagation_mode:
+                    if mode_tag in PROPAGATION_MODES:
+                        self.propagation_mode = PROPAGATION_MODES[mode_tag]
+                    else:
+                        self.propagation_mode = mode_tag
+                        logging.info("Seen a new propagation mode tag not yet in the system: {}", mode_tag)
+
         # DX Grid to lat/lon and vice versa in case one is missing
         if self.dx_grid and not self.dx_latitude:
             try:
diff --git a/templates/add_spot.html b/templates/add_spot.html
index 966ec3d..2088db5 100644
--- a/templates/add_spot.html
+++ b/templates/add_spot.html
@@ -76,7 +76,7 @@
 
 </div>
 
-<script src="/js/add-spot.js?v=1782029759"></script>
+<script src="/js/add-spot.js?v=1782030630"></script>
 <script>$(document).ready(function () {
     $("#nav-link-add-spot").addClass("active");
 }); <!-- highlight active page in nav --></script>
diff --git a/templates/alerts.html b/templates/alerts.html
index 384598a..3d40888 100644
--- a/templates/alerts.html
+++ b/templates/alerts.html
@@ -75,7 +75,7 @@
 
 </div>
 
-<script src="/js/alerts.js?v=1782029759"></script>
+<script src="/js/alerts.js?v=1782030630"></script>
 <script>$(document).ready(function () {
     $("#nav-link-alerts").addClass("active");
 }); <!-- highlight active page in nav --></script>
diff --git a/templates/bands.html b/templates/bands.html
index 178145c..2b5582a 100644
--- a/templates/bands.html
+++ b/templates/bands.html
@@ -77,8 +77,8 @@
 <script>
     let spotProvidersEnabledByDefault = {% raw json_encode(web_ui_options["spot-providers-enabled-by-default"]) %};
 </script>
-<script src="/js/spotsbandsandmap.js?v=1782029759"></script>
-<script src="/js/bands.js?v=1782029759"></script>
+<script src="/js/spotsbandsandmap.js?v=1782030630"></script>
+<script src="/js/bands.js?v=1782030630"></script>
 <script>$(document).ready(function () {
     $("#nav-link-bands").addClass("active");
 }); <!-- highlight active page in nav --></script>
diff --git a/templates/base.html b/templates/base.html
index 361d970..b03764a 100644
--- a/templates/base.html
+++ b/templates/base.html
@@ -1,6 +1,6 @@
 {% extends "skeleton.html" %}
 {% block head_extra %}
-<link rel="stylesheet" href="/css/style.css?v=1782029759" type="text/css">
+<link rel="stylesheet" href="/css/style.css?v=1782030630" type="text/css">
 <link href="/vendor/css/bootstrap-5.3.8.min.css" rel="stylesheet">
 <link href="/vendor/css/fontawesome-6.7.2.min.css" rel="stylesheet">
 <link href="/vendor/css/solid-6.7.2.min.css" rel="stylesheet">
@@ -10,10 +10,10 @@
 <script src="/vendor/js/bootstrap-5.3.8.bundle.min.js"></script>
 <script src="/vendor/js/tinycolor2-1.6.0.min.js"></script>
 
-<script src="/js/utils.js?v=1782029759"></script>
-<script src="/js/ui-ham.js?v=1782029759"></script>
-<script src="/js/geo.js?v=1782029759"></script>
-<script src="/js/common.js?v=1782029759"></script>
+<script src="/js/utils.js?v=1782030630"></script>
+<script src="/js/ui-ham.js?v=1782030630"></script>
+<script src="/js/geo.js?v=1782030630"></script>
+<script src="/js/common.js?v=1782030630"></script>
 {% end %}
 {% block body %}
 <div class="container">
diff --git a/templates/conditions.html b/templates/conditions.html
index 835522e..8bd545b 100644
--- a/templates/conditions.html
+++ b/templates/conditions.html
@@ -284,7 +284,7 @@
 </div>
 
 <script src="/vendor/js/chart-4.4.9.umd.min.js"></script>
-<script src="/js/conditions.js?v=1782029759"></script>
+<script src="/js/conditions.js?v=1782030630"></script>
 <script>$(document).ready(function () {
     $("#nav-link-conditions").addClass("active");
 }); <!-- highlight active page in nav --></script>
diff --git a/templates/map.html b/templates/map.html
index 7948b9f..77ef68f 100644
--- a/templates/map.html
+++ b/templates/map.html
@@ -95,8 +95,8 @@
 <script>
     let spotProvidersEnabledByDefault = {% raw json_encode(web_ui_options["spot-providers-enabled-by-default"]) %};
 </script>
-<script src="/js/spotsbandsandmap.js?v=1782029759"></script>
-<script src="/js/map.js?v=1782029759"></script>
+<script src="/js/spotsbandsandmap.js?v=1782030630"></script>
+<script src="/js/map.js?v=1782030630"></script>
 <script>$(document).ready(function () {
     $("#nav-link-map").addClass("active");
 }); <!-- highlight active page in nav --></script>
diff --git a/templates/spots.html b/templates/spots.html
index 09330bd..a8e8ef7 100644
--- a/templates/spots.html
+++ b/templates/spots.html
@@ -116,8 +116,8 @@
 <script>
     let spotProvidersEnabledByDefault = {% raw json_encode(web_ui_options["spot-providers-enabled-by-default"]) %};
 </script>
-<script src="/js/spotsbandsandmap.js?v=1782029759"></script>
-<script src="/js/spots.js?v=1782029759"></script>
+<script src="/js/spotsbandsandmap.js?v=1782030630"></script>
+<script src="/js/spots.js?v=1782030630"></script>
 <script>$(document).ready(function () {
     $("#nav-link-spots").addClass("active");
 }); <!-- highlight active page in nav --></script>
diff --git a/templates/status.html b/templates/status.html
index 6cd615c..f84de02 100644
--- a/templates/status.html
+++ b/templates/status.html
@@ -59,7 +59,7 @@
     </div>
 </div>
 
-<script src="/js/status.js?v=1782029759"></script>
+<script src="/js/status.js?v=1782030630"></script>
 <script>
     $(document).ready(function () {
         $("#nav-link-status").addClass("active");