diff --git a/content/guides/additional/parsing.md b/content/guides/additional/parsing.md
index 61fb62e..699fa75 100644
--- a/content/guides/additional/parsing.md
+++ b/content/guides/additional/parsing.md
@@ -274,6 +274,25 @@ One common scenario where `+cold` sees play is when writing [command line
 interface (CLI) apps](/guides/additional/cli-tutorial). We usher the
 reader there to find an example where `+cold` is used.
 
+### [`+less`](/reference/hoon/stdlib/4f/#less)
+
+`+less` builds a `rule` to exclude matches to its first argument.  It is commonly
+used to filter out an undesired match.
+
+```
+> (;~(less buc next) [[1 1] " "])
+[p=[p=1 q=2] q=[~ [p=' ' q=[p=[p=1 q=2] q=""]]]]
+
+> (;~(less ace next) [[1 1] " "])
+[p=[p=1 q=1] q=~]
+```
+
+Here we see that the first case refuses to parse `buc` `$` (which is not present), so
+the `ace` ` ` succeeds (via `+next` which matches any character).
+
+The second case attempts to parse the excluded character `ace` ` ` and fails on the
+first character as it should.
+
 ### [`+knee`](/reference/hoon/stdlib/4f/#knee)
 
 Another important function in the parser builder library is `+knee`, used for building