diff --git a/README.md b/README.md
index 747abd1..5f86a19 100644
--- a/README.md
+++ b/README.md
@@ -30,5 +30,4 @@ Implemented as a header only library.
 
 
 **optstring:** Complies with GNU getopt's optstring. That is:
-
-optstring  is  a  string  containing the legitimate option characters. A legitimate option character is any visible one byte ascii(7) character (for which isgraph(3) would return nonzero) that is not '-', ':', or ';'.  If such a character is followed by a colon, the option requires an argument [...]  Two colons mean an option takes an optional arg [...]
+*optstring  is  a  string  containing the legitimate option characters. A legitimate option character is any visible one byte ascii(7) character (for which isgraph(3) would return nonzero) that is not '-', ':', or ';'.  If such a character is followed by a colon, the option requires an argument [...]  Two colons mean an option takes an optional arg [...]*