Signlang should now work while muzzled.

code/modules/mob/living/say.dm

@@ -177,7 +177,7 @@ proc/get_radio_key_from_channel(var/channel)
 		return 1
 
 	//Self explanatory.
-	if(is_muzzled())
+	if(is_muzzled() && !(speaking && (speaking.flags & SIGNLANG)))
 		src << "<span class='danger'>You're muzzled and cannot speak!</span>"
 		return
 
@@ -204,7 +204,7 @@ proc/get_radio_key_from_channel(var/channel)
 		w_not_heard = "[speaking.speech_verb] something [w_adverb]"
 
 	//For speech disorders (hulk, slurring, stuttering)
-	if(!(speaking && (speaking.flags & NO_STUTTER)))
+	if(!(speaking && (speaking.flags & NO_STUTTER || speaking.flags & SIGNLANG)))
 		var/list/message_data = list(message, verb, whispering)
 		if(handle_speech_problems(message_data))
 			message = message_data[1]

html/changelogs/Anewbe - SignMuzzle.yml

@@ -0,0 +1,36 @@
+################################
+# Example Changelog File
+#
+# Note: This file, and files beginning with ".", and files that don't end in ".yml" will not be read. If you change this file, you will look really dumb.
+#
+# Your changelog will be merged with a master changelog. (New stuff added only, and only on the date entry for the day it was merged.)
+# When it is, any changes listed below will disappear.
+#
+# Valid Prefixes: 
+#   bugfix
+#   wip (For works in progress)
+#   tweak
+#   soundadd
+#   sounddel
+#   rscadd (general adding of nice things)
+#   rscdel (general deleting of nice things)
+#   imageadd
+#   imagedel
+#   maptweak
+#   spellcheck (typo fixes)
+#   experiment
+#################################
+
+# Your name.  
+author: Anewbe
+
+# Optional: Remove this file after generating master changelog.  Useful for PR changelogs that won't get used again.
+delete-after: True
+
+# Any changes you've made.  See valid prefix list above.
+# INDENT WITH TWO SPACES.  NOT TABS.  SPACES.
+# SCREW THIS UP AND IT WON'T WORK.
+# Also, all entries are changed into a single [] after a master changelog generation. Just remove the brackets when you add new entries.
+# Please surround your changes in  double quotes ("), as certain characters otherwise screws up compiling. The quotes will not show up in the changelog.
+changes: 
+  - bugfix: "Sign language can now be used while muzzled."