%% in format string = literal %

src/General/Settings.coffee

@@ -408,7 +408,7 @@ Settings =
   time: ->
     @nextElementSibling.textContent = Time.format @value, new Date()
   backlink: ->
-    @nextElementSibling.textContent = @value.replace /%id/, '123456789'
+    @nextElementSibling.textContent = @value.replace /%(?:id|%)/g, (x) -> {'%id': '123456789', '%%': '%'}[x]
   fileInfo: ->
     data =
       isReply: true

src/General/html/Settings/Advanced.html

@@ -47,6 +47,7 @@
   <div>Hour: <code>%k</code>, <code>%H</code>, <code>%l</code>, <code>%I</code>, <code>%p</code>, <code>%P</code></div>
   <div>Minute: <code>%M</code></div>
   <div>Second: <code>%S</code></div>
+  <div>Literal <code>%</code>: <code>%%</code></div>
 </fieldset>
 
 <fieldset>
@@ -62,6 +63,7 @@
   <div>Spoiler indicator: <code>%p</code></div>
   <div>Size: <code>%B</code> (Bytes), <code>%K</code> (KB), <code>%M</code> (MB), <code>%s</code> (4chan default)</div>
   <div>Resolution: <code>%r</code> (Displays 'PDF' for PDF files)</div>
+  <div>Literal <code>%</code>: <code>%%</code></div>
 </fieldset>
 
 <fieldset>

src/General/html/Settings/Sauce.html

@@ -7,5 +7,6 @@
   <li><code>%MD5</code>: MD5 hash.</li>
   <li><code>%name</code>: Original file name.</li>
   <li><code>%board</code>: Current board.</li>
+  <li><code>%%</code>: Literal <code>%</code>.</li>
 </ul>
 <textarea name=sauces class=field spellcheck=false></textarea>

src/Images/Sauce.coffee

@@ -19,17 +19,19 @@ Sauce =
     link = link.replace /;text:.+$/, ''
     parts = [link, text]
     for i in [0..1]
-      parts[i] = parts[i].replace /%(T?URL|MD5|board|name)/g, (parameter) ->
-        if type = {
+      parts[i] = parts[i].replace /%(T?URL|MD5|board|name|%)/g, (parameter) ->
+        type = {
           '%TURL':  post.file.thumbURL
           '%URL':   post.file.URL
           '%MD5':   post.file.MD5
           '%board': post.board
           '%name':  post.file.name
+          '%%':     '%'
         }[parameter]
-          if i is 0 then encodeURIComponent(type) else type
+        if i is 0 and parameter isnt '%%'
+          encodeURIComponent type
         else
-          parameter
+          type
     a.href = parts[0]
     a.textContent = parts[1]
     a

src/Miscellaneous/FileInfo.coffee

@@ -11,7 +11,7 @@ FileInfo =
     FileInfo.format Conf['fileInfo'], @, @file.text.firstElementChild
   format: (formatString, post, outputNode) ->
     output = innerHTML: ''
-    formatString.replace /%([A-Za-z])|[^%]+/g, (s, c) ->
+    formatString.replace /%(.)|[^%]+/g, (s, c) ->
       if c of FileInfo.formatters
         FileInfo.formatters[c].call post, output
       else
@@ -60,3 +60,5 @@ FileInfo =
     r: (x) ->
       dim = @file.dimensions or 'PDF'
       x.innerHTML += E dim
+    '%': (x) ->
+      x.innerHTML += '%'

src/Miscellaneous/Time.coffee

@@ -9,7 +9,7 @@ Time =
     return if @isClone
     @nodes.date.textContent = Time.format Conf['time'], @info.date
   format: (formatString, date) ->
-    formatString.replace /%([A-Za-z])/g, (s, c) ->
+    formatString.replace /%(.)/g, (s, c) ->
       if c of Time.formatters
         Time.formatters[c].call(date)
       else
@@ -56,3 +56,4 @@ Time =
     S: -> Time.zeroPad @getSeconds()
     y: -> @getFullYear().toString()[2..]
     Y: -> @getFullYear()
+    '%': -> '%'

src/Quotelinks/QuoteBacklink.coffee

@@ -26,7 +26,7 @@ QuoteBacklink =
     a = $.el 'a',
       href: Build.postURL @board.ID, @thread.ID, @ID
       className: if @isHidden then 'filtered backlink' else 'backlink'
-      textContent: (Conf['backlink'].replace /%id/, @ID) + (if markYours then '\u00A0(You)' else '')
+      textContent: Conf['backlink'].replace(/%(?:id|%)/g, (x) => {'%id': @ID, '%%': '%'}[x]) + (if markYours then '\u00A0(You)' else '')
     for quote in @quotes
       containers = [QuoteBacklink.getContainer quote]
       if (post = g.posts[quote]) and post.nodes.backlinkContainer