diff --git a/doc/bulb.1 b/doc/bulb.1
index 4c4394f..f4178c0 100644
--- a/doc/bulb.1
+++ b/doc/bulb.1
@@ -35,12 +35,23 @@ Posts a message read from the standard input. See the STANDARD INPUT section.
 .IP \fB-u\fP
 Operates undercover. All posts made will be under the name \(lqanonymous\(rq.
 .\"
+.SH ENVIRONMENT
+
+The BULBPATH environment variable specifies a colon-separated list of
+directories (much like PATH) in which to search for boards. Directories at the
+start take precedence over directories at the end. It has a value of
+.I /var/bulb
+by default.
+.SH FILES
+.I /var/bulb/*
+.\"
 .SH STANDARD INPUT
 
 When the
 .B -p
-option is supplied, the standard input will be read until EOF. It will be posted
-under the name of the current user in whichever board the user selected.
+option is supplied, the standard input will be read until EOF. The resulting
+text will be posted under the name of the current user in whichever board is
+selected.
 .\"
 .SH STANDARD OUTPUT