Index: src/branch.c
==================================================================
--- src/branch.c
+++ src/branch.c
@@ -683,11 +683,10 @@
   style_set_current_feature("branch");
   style_header("Branches");
   style_submenu_element("List", "brlist");
   login_anonymous_available();
   timeline_ss_submenu();
-  cookie_render();
   @ <h2>The initial check-in for each branch:</h2>
   blob_append(&sql, timeline_query_for_www(), -1);
   blob_append_sql(&sql,
     "AND blob.rid IN (SELECT rid FROM tagxref"
     "                  WHERE tagtype>0 AND tagid=%d AND srcid!=0)", TAG_BRANCH);

Index: src/cgi.c
==================================================================
--- src/cgi.c
+++ src/cgi.c
@@ -1159,16 +1159,28 @@
 #endif
   z = (char*)P("HTTP_COOKIE");
   if( z ){
     z = fossil_strdup(z);
     add_param_list(z, ';');
+    z = (char*)cookie_value("skin",0);
+    if(z){
+      skin_use_alternative(z, 2);
+    }
   }
 
   z = (char*)P("QUERY_STRING");
   if( z ){
     z = fossil_strdup(z);
     add_param_list(z, '&');
+    z = (char*)P("skin");
+    if(z){
+      char *zErr = skin_use_alternative(z, 2);
+      if(!zErr){
+        cookie_write_parameter("skin","skin",z);
+      }
+      fossil_free(zErr);
+    }
   }
 
   z = (char*)P("REMOTE_ADDR");
   if( z ){
     g.zIpAddr = fossil_strdup(z);

Index: src/cookies.c
==================================================================
--- src/cookies.c
+++ src/cookies.c
@@ -173,15 +173,16 @@
   const char *zDflt      /* Default value for the parameter */
 ){
   cookie_readwrite(zQP, zPName, zDflt, COOKIE_READ|COOKIE_WRITE);
 }
 
-/* Update the user preferences cookie, if necessary, and shut down this
-** module
+/* Update the user preferences cookie, if necessary, and shut down
+** this module. The cookie is only emitted if its value has actually
+** changed since the request started.
 */
 void cookie_render(void){
-  if( cookies.bChanged && P("udc")!=0 ){
+  if( cookies.bChanged ){
     Blob new;
     int i;
     blob_init(&new, 0, 0);
     for(i=0;i<cookies.nParam;i++){
       if( i>0 ) blob_append(&new, ",", 1);

Index: src/descendants.c
==================================================================
--- src/descendants.c
+++ src/descendants.c
@@ -565,11 +565,10 @@
   url_reset(&url);
   style_set_current_feature("leaves");
   style_header("Leaves");
   login_anonymous_available();
   timeline_ss_submenu();
-  cookie_render();
 #if 0
   style_sidebox_begin("Nomenclature:", "33%");
   @ <ol>
   @ <li> A <div class="sideboxDescribed">leaf</div>
   @ is a check-in with no descendants in the same branch.</li>

Index: src/finfo.c
==================================================================
--- src/finfo.c
+++ src/finfo.c
@@ -364,11 +364,10 @@
   url_initialize(&url, "finfo");
   if( brBg ) url_add_parameter(&url, "brbg", 0);
   if( uBg ) url_add_parameter(&url, "ubg", 0);
   ridFrom = name_to_rid_www("from");
   zPrevDate[0] = 0;
-  cookie_render();
   if( fnid==0 ){
     @ No such file: %h(zFilename)
     style_finish_page();
     return;
   }

Index: src/info.c
==================================================================
--- src/info.c
+++ src/info.c
@@ -939,11 +939,10 @@
     append_file_change_line(zUuid, zName, zOld, zNew, zOldName, 
                             diffFlags,pRe,mperm);
   }
   db_finalize(&q3);
   append_diff_javascript(diffType==2);
-  cookie_render();
   style_finish_page();
 }
 
 /*
 ** WEBPAGE: winfo
@@ -1185,11 +1184,10 @@
   login_check_credentials();
   if( !g.perm.Read ){ login_needed(g.anon.Read); return; }
   login_anonymous_available();
   load_control();
   diffType = preferred_diff_type();
-  cookie_render();
   zRe = P("regex");
   if( zRe ) re_compile(&pRe, zRe, 0);
   zBranch = P("branch");
   if( zBranch && zBranch[0]==0 ) zBranch = 0;
   if( zBranch ){
@@ -1706,11 +1704,10 @@
   int verbose = PB("verbose");
 
   login_check_credentials();
   if( !g.perm.Read ){ login_needed(g.anon.Read); return; }
   diffType = preferred_diff_type();
-  cookie_render();
   if( P("from") && P("to") ){
     v1 = artifact_from_ci_and_filename("from");
     v2 = artifact_from_ci_and_filename("to");
   }else{
     Stmt q;

Index: src/main.c
==================================================================
--- src/main.c
+++ src/main.c
@@ -1838,33 +1838,11 @@
     zPathInfo += 7;
     g.nExtraURL += 7;
     cgi_replace_parameter("PATH_INFO", zPathInfo);
     cgi_replace_parameter("SCRIPT_NAME", zNewScript);
     etag_cancel();
-  }else if( zPathInfo && strncmp(zPathInfo, "/skn_", 5)==0 ){
-    int i;
-    char *zAlt;
-    char *zErr;
-    char *z;
-    while( (z = strstr(zPathInfo+1,"/skn_"))!=0 ) zPathInfo = z;
-    for(i=5; zPathInfo[i] && zPathInfo[i]!='/'; i++){}
-    zAlt = mprintf("%.*s", i-5, zPathInfo+5);
-    zErr = skin_use_alternative(zAlt);
-    if( zErr ){
-      fossil_free(zErr);
-    }else{
-      char *zNewScript;
-      zNewScript = mprintf("%T/skn_%s", P("SCRIPT_NAME"), zAlt);
-      if( g.zTop ) g.zTop = mprintf("%R/skn_%s", zAlt);
-      if( g.zBaseURL ) g.zBaseURL = mprintf("%s/skn_%s", g.zBaseURL, zAlt);
-      zPathInfo += i;
-      g.nExtraURL += i;
-      cgi_replace_parameter("PATH_INFO", zPathInfo);
-      cgi_replace_parameter("SCRIPT_NAME", zNewScript);
-    }
-    fossil_free(zAlt);
-  }  
+  }
 
   /* If the content type is application/x-fossil or 
   ** application/x-fossil-debug, then a sync/push/pull/clone is
   ** desired, so default the PATH_INFO to /xfer
   */
@@ -2378,11 +2356,11 @@
       ** Use one of the built-in skins defined by LABEL.  LABEL is the
       ** name of the subdirectory under the skins/ directory that holds
       ** the elements of the built-in skin.  If LABEL does not match,
       ** this directive is a silent no-op.
       */
-      skin_use_alternative(blob_str(&value));
+      fossil_free(skin_use_alternative(blob_str(&value), 1));
       blob_reset(&value);
       continue;
     }
     if( blob_eq(&key, "jsmode:") && blob_token(&line, &value) ){
       /* jsmode: MODE

Index: src/skins.c
==================================================================
--- src/skins.c
+++ src/skins.c
@@ -104,21 +104,61 @@
 **
 ** If the alternative skin name contains one or more '/' characters, then
 ** it is assumed to be a directory on disk that holds override css.txt,
 ** footer.txt, and header.txt.  This mode can be used for interactive
 ** development of new skins.
+**
+** The 2nd parameter is a ranking of how important this alternative
+** skin declaration is, and lower values trump higher ones. If a call
+** to this function passes a higher-valued rank than a previous call,
+** the subsequent call becomes a no-op. Only calls with the same or
+** lower rank (i.e. higher priority) will overwrite a previous
+** setting. This approach is used because the CGI/server-time
+** initialization happens in an order which is incompatible with our
+** preferred ranking, making it otherwise more invasive to tell the
+** internals "the --skin flag ranks higher than a URL parameter" (the
+** former gets initialized before both URL parameters and the /draft
+** path determination).
+**
+** The rankings were initially defined in
+** https://fossil-scm.org/forum/forumpost/caf8c9a8bb
+** and are:
+**
+** 0) A skin name matching the glob draft[1-9] trumps everything else.
+**
+** 1) The --skin flag or skin: CGI config setting.
+**
+** 2) The "skin" display setting cookie or URL argument, in that
+** order. If the "skin" URL argument is provided and refers to a legal
+** skin then that will update the display cookie. If the skin name is
+** illegal it is silently ignored.
+**
+** 3) Skin properties from the CONFIG db table
+**
+** 4) Default skin.
+**
+** As a special case, the name "_repo" resets zAltSkinDir and
+** pAltSkin to 0 to indicate that the current config-side skin should
+** be used (rank 3, above), then returns 0.
 */
-char *skin_use_alternative(const char *zName){
+char *skin_use_alternative(const char *zName, int rank){
+  static int currentRank = 5;
   int i;
   Blob err = BLOB_INITIALIZER;
-  if( strchr(zName, '/')!=0 ){
+  if(rank > currentRank) return 0;
+  if( 1==rank && strchr(zName, '/')!=0 ){
     zAltSkinDir = fossil_strdup(zName);
     return 0;
   }
   if( sqlite3_strglob("draft[1-9]", zName)==0 ){
     skin_use_draft(zName[5] - '0');
     return 0;
+  }
+  if(zName && 0==strcmp("_repo",zName)){
+    pAltSkin = 0;
+    zAltSkinDir = 0;
+    return 0;
   }
   for(i=0; i<count(aBuiltinSkin); i++){
     if( fossil_strcmp(aBuiltinSkin[i].zLabel, zName)==0 ){
       pAltSkin = &aBuiltinSkin[i];
       return 0;
@@ -137,11 +177,11 @@
 ** call fossil_fatal() if an unknown skin is specified.
 */
 void skin_override(void){
   const char *zSkin = find_option("skin",0,1);
   if( zSkin ){
-    char *zErr = skin_use_alternative(zSkin);
+    char *zErr = skin_use_alternative(zSkin, 1);
     if( zErr ) fossil_fatal("%s", zErr);
   }
 }
 
 /*
@@ -1154,24 +1194,32 @@
     }
     fossil_free(zPattern);
   } 
   login_check_credentials();
   style_header("Skins");
+  if(zAltSkinDir && zAltSkinDir[0]){
+    @ <p class="warning">Warning: this fossil instance was started with
+    @ a hard-coded skin value which trumps any option selected below.
+    @ A skins selected below will be recorded in your prefere cookie
+    @ but will not be used until/unless the site administrator
+    @ configures the site to run without a forced hard-coded skin.
+    @ </p>
+  }
   @ <p>The following skins are available for this repository:</p>
   @ <ul>
   if( pAltSkin==0 && zAltSkinDir==0 && iDraftSkin==0 ){
     @ <li> Standard skin for this repository &larr; <i>Currently in use</i>
   }else{
-    @ <li> %z(href("%s/skins",zBase))Standard skin for this repository</a>
+    @ <li> %z(href("%R/skins?skin=_repo"))Standard skin for this repository</a>
   }
   for(i=0; i<count(aBuiltinSkin); i++){
     if( pAltSkin==&aBuiltinSkin[i] ){
       @ <li> %h(aBuiltinSkin[i].zDesc) &larr; <i>Currently in use</i>
     }else{
-      char *zUrl = href("%s/skn_%s/skins", zBase, aBuiltinSkin[i].zLabel);
+      char *zUrl = href("%R/skins?skin=%T", aBuiltinSkin[i].zLabel);
       @ <li> %z(zUrl)%h(aBuiltinSkin[i].zDesc)</a>
     }
   }
   @ </ul>
   style_finish_page();
   fossil_free(zBase);
 }

Index: src/style.c
==================================================================
--- src/style.c
+++ src/style.c
@@ -1011,10 +1011,14 @@
   if( sqlite3_strlike("%</body>%", zFooter, 0)!=0 ){
     style_load_all_js_files();
     @ </body>
     @ </html>
   }
+  /* Update the user display prefs cookie if it was modified during
+  ** this request.
+  */
+  cookie_render();
 }
 
 /*
 ** Begin a side-box on the right-hand side of a page.  The title and
 ** the width of the box are given as arguments.  The width is usually

Index: src/tag.c
==================================================================
--- src/tag.c
+++ src/tag.c
@@ -755,11 +755,10 @@
 
   style_header("Tagged Check-ins");
   style_submenu_element("List", "taglist");
   login_anonymous_available();
   timeline_ss_submenu();
-  cookie_render();
   @ <h2>Check-ins with non-propagating tags:</h2>
   blob_append(&sql, timeline_query_for_www(), -1);
   blob_append_sql(&sql,
     "AND blob.rid IN (SELECT rid FROM tagxref"
     "                  WHERE tagtype=1 AND srcid>0"

Index: src/timeline.c
==================================================================
--- src/timeline.c
+++ src/timeline.c
@@ -1754,11 +1754,10 @@
     cgi_set_parameter("y", zType);
   }
   if( zType[0]=='a' || zType[0]=='c' ){
     cookie_write_parameter("y","y",zType);
   }
-  cookie_render();
 
   /* Convert the cf=FILEHASH query parameter into a c=CHECKINHASH value */
   if( P("cf")!=0 ){
     zCirca = db_text(0,
       "SELECT (SELECT uuid FROM blob WHERE rid=mlink.mid)"

Index: www/changes.wiki
==================================================================
--- www/changes.wiki
+++ www/changes.wiki
@@ -21,24 +21,25 @@
      check-in.
   *  The "pikchr-background" settings is now available in 
      "detail.txt" skin files, for better control of Pikchr
      colors in inverted color schemes.
   *  The hamburger menu is now available on the built-in
-     "[/skn_ardoise/doc/trunk/www/changes.wiki#v2_15|ardoise]" and
-     "[/skn_plain_gray/doc/trunk/www/changes.wiki#v2_15|plain_gray]"
+     "[/doc/trunk/www/changes.wiki?skin=ardoise#v2_15|ardoise]" and
+     "[/doc/trunk/www/changes.wiki?skin=plain_gray#v2_15|plain_gray]"
      skins.
-  *  Add the --list option to the 
+  *  Add the <tt>--list</tt> option to the 
      [/help?cmd=tarball|tarball],
      [/help?cmd=zip|zip], and [/help?cmd=sqlar|sqlar]
      commands.
   *  The javascript used to implement the hamburger menu on the
      default built-in skin has been made generic so that it is usable
      by a variety of skins, and promoted to an ordinary built-in
      javascript file.
   *  Any built-in skin named "X" can be used instead of the standard
-     repository skin by including the term "skn_X" at the beginning
-     of the URL path.
+     repository skin by adding the URL parameter <tt>skin=X</tt> to the
+     request, and that selection is persistent using a cookie. The
+     [/skins] page may be used to select a skin.
   *  New TH1 commands:  "builtin_request_js", "capexpr",
      "foreach", "string match"
 
 <a name='v2_14'></a>
 <h2>Changes for Version 2.14 (2021-01-20)</h2>