diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index 1a9e4f3..d68d4d8 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -4430,9 +4430,18 @@
 		message will appear and the match will not be added.  An ID
 		is specified as a positive integer (zero excluded).  IDs 1, 2
 		and 3 are reserved for |:match|, |:2match| and |:3match|,
-		respectively.  If the {id} argument is not specified,
+		respectively.  If the {id} argument is not specified or -1,
 		|matchadd()| automatically chooses a free ID.
 
+		The optional {dict} argmument allows for further custom
+		values. Currently this is used to specify a match specifc
+		conceal character that will be shown for |hl-Conceal|
+		highlighted matches. The dict can have the following members:
+
+			conceal	    Special character to show instead of the
+				    match (only for |hl-Conceal| highlighed
+				    matches, see |:syn-cchar|)
+
 		The number of matches is not limited, as it is the case with
 		the |:match| commands.
 
@@ -4446,7 +4455,7 @@
 		available from |getmatches()|.	All matches can be deleted in
 		one operation by |clearmatches()|.
 
-matchaddpos({group}, {pos}[, {priority}[, {id}]])		*matchaddpos()*
+matchaddpos({group}, {pos}[, {priority}[, {id}[, {dict}]]])		*matchaddpos()*
 		Same as |matchadd()|, but requires a list of positions {pos}
 		instead of a pattern. This command is faster than |matchadd()|
 		because it does not require to handle regular expressions and