diff --git a/man/rgbgfx.1 b/man/rgbgfx.1
index cfeb482f..98c51b5d 100644
--- a/man/rgbgfx.1
+++ b/man/rgbgfx.1
@@ -374,14 +374,18 @@ can be used in an at-file (with identical semantics), it is only effective insid
 .Sh PALETTE SPECIFICATION FORMATS
 The following formats are supported:
 .Bl -tag -width Ds
-.It Sy act
+.It Cm act
 .Lk https://www.adobe.com/devnet-apps/photoshop/fileformatashtml/#50577411_pgfId-1070626 Adobe Photoshop color table .
-.It Sy aco
+.It Cm aco
 .Lk https://www.adobe.com/devnet-apps/photoshop/fileformatashtml/#50577411_pgfId-1055819 Adobe Photoshop color swatch .
-.It Sy psp
-.Lk https://www.selapa.net/swatches/colors/fileformats.php#psp_pal Paint Shop Pro palette .
-.It Sy gpl
+.It Cm gbc
+A GBC palette memory dump, as emitted by
+.Nm Fl p .
+Useful to force several images to share the same palette.
+.It Cm gpl
 .Lk https://docs.gimp.org/2.10/en/gimp-concepts-palettes.html GIMP palette .
+.It Cm psp
+.Lk https://www.selapa.net/swatches/colors/fileformats.php#psp_pal Paint Shop Pro palette .
 .El
 .Pp
 If you wish for another format to be supported, please open an issue (see