diff --git a/server/handlers/api/options.py b/server/handlers/api/options.py
index f9b66dd..4529e53 100644
--- a/server/handlers/api/options.py
+++ b/server/handlers/api/options.py
@@ -8,7 +8,7 @@ from tornado import httputil
 from tornado.web import Application
 
 from core.config import MAX_SPOT_AGE, ALLOW_SPOTTING
-from core.constants import BANDS, ALL_MODES, MODE_TYPES, SIGS, CONTINENTS
+from core.constants import BANDS, ALL_MODES, MODE_TYPES, SIGS, CONTINENTS, PROPAGATION_MODES
 from core.prometheus_metrics_handler import api_requests_counter
 from core.utils import serialize_everything
 
@@ -42,6 +42,7 @@ class APIOptionsHandler(tornado.web.RequestHandler):
                    "alert_sources": list(
                        map(lambda p: p["name"], filter(lambda p: p["enabled"], self._status_data["alert_providers"]))),
                    "continents": CONTINENTS,
+                   "propagation_modes": PROPAGATION_MODES.values(),
                    "max_spot_age": MAX_SPOT_AGE,
                    "spot_allowed": ALLOW_SPOTTING}
         # If spotting to this server is enabled, "API" is another valid spot source even though it does not come from
diff --git a/templates/add_spot.html b/templates/add_spot.html
index 2088db5..fa4ddc4 100644
--- a/templates/add_spot.html
+++ b/templates/add_spot.html
@@ -76,7 +76,7 @@
 
 </div>
 
-<script src="/js/add-spot.js?v=1782030630"></script>
+<script src="/js/add-spot.js?v=1782036161"></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 3d40888..a019df2 100644
--- a/templates/alerts.html
+++ b/templates/alerts.html
@@ -75,7 +75,7 @@
 
 </div>
 
-<script src="/js/alerts.js?v=1782030630"></script>
+<script src="/js/alerts.js?v=1782036161"></script>
 <script>$(document).ready(function () {
     $("#nav-link-alerts").addClass("active");
 }); <!-- highlight active page in nav --></script>
diff --git a/templates/bands.html b/templates/bands.html
index 2b5582a..600bf17 100644
--- a/templates/bands.html
+++ b/templates/bands.html
@@ -77,8 +77,8 @@
 <script>
     let spotProvidersEnabledByDefault = {% raw json_encode(web_ui_options["spot-providers-enabled-by-default"]) %};
 </script>
-<script src="/js/spotsbandsandmap.js?v=1782030630"></script>
-<script src="/js/bands.js?v=1782030630"></script>
+<script src="/js/spotsbandsandmap.js?v=1782036161"></script>
+<script src="/js/bands.js?v=1782036161"></script>
 <script>$(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 b03764a..745727e 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=1782030630" type="text/css">
+<link rel="stylesheet" href="/css/style.css?v=1782036161" 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=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>
+<script src="/js/utils.js?v=1782036161"></script>
+<script src="/js/ui-ham.js?v=1782036161"></script>
+<script src="/js/geo.js?v=1782036161"></script>
+<script src="/js/common.js?v=1782036161"></script>
 {% end %}
 {% block body %}
 <div class="container">
diff --git a/templates/conditions.html b/templates/conditions.html
index 8bd545b..19ad0b1 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=1782030630"></script>
+<script src="/js/conditions.js?v=1782036161"></script>
 <script>$(document).ready(function () {
     $("#nav-link-conditions").addClass("active");
 }); <!-- highlight active page in nav --></script>
diff --git a/templates/map.html b/templates/map.html
index 77ef68f..5759bbd 100644
--- a/templates/map.html
+++ b/templates/map.html
@@ -95,8 +95,8 @@
 <script>
     let spotProvidersEnabledByDefault = {% raw json_encode(web_ui_options["spot-providers-enabled-by-default"]) %};
 </script>
-<script src="/js/spotsbandsandmap.js?v=1782030630"></script>
-<script src="/js/map.js?v=1782030630"></script>
+<script src="/js/spotsbandsandmap.js?v=1782036161"></script>
+<script src="/js/map.js?v=1782036161"></script>
 <script>$(document).ready(function () {
     $("#nav-link-map").addClass("active");
 }); <!-- highlight active page in nav --></script>
diff --git a/templates/spots.html b/templates/spots.html
index a8e8ef7..697c36c 100644
--- a/templates/spots.html
+++ b/templates/spots.html
@@ -116,8 +116,8 @@
 <script>
     let spotProvidersEnabledByDefault = {% raw json_encode(web_ui_options["spot-providers-enabled-by-default"]) %};
 </script>
-<script src="/js/spotsbandsandmap.js?v=1782030630"></script>
-<script src="/js/spots.js?v=1782030630"></script>
+<script src="/js/spotsbandsandmap.js?v=1782036161"></script>
+<script src="/js/spots.js?v=1782036161"></script>
 <script>$(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 f84de02..0b95a4a 100644
--- a/templates/status.html
+++ b/templates/status.html
@@ -59,7 +59,7 @@
     </div>
 </div>
 
-<script src="/js/status.js?v=1782030630"></script>
+<script src="/js/status.js?v=1782036161"></script>
 <script>
     $(document).ready(function () {
         $("#nav-link-status").addClass("active");
diff --git a/webassets/apidocs/openapi.yml b/webassets/apidocs/openapi.yml
index f78d45f..030808b 100644
--- a/webassets/apidocs/openapi.yml
+++ b/webassets/apidocs/openapi.yml
@@ -14,6 +14,10 @@ info:
     Spothole's source code is located at https://git.ianrenton.com/ian/spothole and the README there provides setup instructions if you would like to run your own copy. A demonstration server of Spothole is located at https://spothole.app.
 
     ## Changelog
+    
+    ### 1.4
+    
+    * Spots can now include a "propagation_mode" field, and the `/options` call enumerates the options that can have.
 
     ### 1.3
 
@@ -36,7 +40,7 @@ info:
   license:
     name: The Unlicense
     url: https://unlicense.org/#the-unlicense
-  version: v1.3
+  version: v1.4
 
 servers:
   - url: https://spothole.app/api/v1
@@ -898,6 +902,20 @@ components:
         - NONE
       example: SPOT
 
+    PropagationMode:
+      type: string
+      enum:
+        - F2 layer ionospheric
+        - Sporadic-E
+        - Tropospheric ducting
+        - Trans-Equatorial Propagation
+        - Earth-Moon-Earth
+        - Aurora
+        - Meteor scatter
+        - Rain scatter
+        - Aircraft scatter
+      example: Sporadic-E
+
     LocationSourceForSpot:
       type: string
       enum:
@@ -1153,6 +1171,11 @@ components:
           type: string
           description: The ID the source gave it, if any.
           example: "GUID-123456"
+        propagation_mode:
+          description: >
+            Propagation mode, if known. This is only populated when the upstream spot specifically states it; Spothole
+            does not try to determine it using its own algorithm.
+          $ref: "#/components/schemas/PropagationMode"
 
 
     SpotStream:
@@ -1827,6 +1850,11 @@ components:
           items:
             type: string
             example: "EU"
+        propagation_modes:
+          type: array
+          description: A list of all the supported propagation mode names.
+          items:
+            $ref: '#/components/schemas/PropagationMode'
         max_spot_age:
           type: integer
           description: >