document core and stack
diff --git a/man/man1/core.1 b/man/man1/core.1
index b0a5b16..51d235f 100644
--- a/man/man1/core.1
+++ b/man/man1/core.1
@@ -4,9 +4,6 @@
.SH SYNOPSIS
.B core
[
-.B -s
-]
-[
.I dir
|
.I corefile
@@ -27,11 +24,18 @@
.PP
For each core file read,
.I core
-prints the date and time the core was generated,
-the command that generated it, and, if the
-.B -s
-option is given, a short stack trace
-at the time of the core dump.
+prints the command
+.B stack
+.IR file ,
+the date and time the core was generated,
+and
+the command that generated it.
+The
+.B stack
+command, if run, prints a stack trace of the
+executing thread at the time of the core dump;
+see
+.IR db (1).
.PP
If no arguments are given,
.I core
@@ -49,7 +53,3 @@
.IR acid (1),
.IR db (1),
.IR core (5)
-.SH BUGS
-The
-.B -s
-option is not implemented.
