diff --git a/docs/file-formats/PAL.md b/docs/file-formats/PAL.md
index d21b75ac..2e724567 100644
--- a/docs/file-formats/PAL.md
+++ b/docs/file-formats/PAL.md
@@ -3,8 +3,28 @@ slug: /file-formats/pal
 title: PAL (Placeholder)
 ---
 
-:::info
+This document describes the PAL file format used in the Ragnarok Online client.
 
-This section is a placeholder. If you know anything about the topic, please help fill it with content!
+## Contents
 
-:::
+PAL files are alternative [color palettes](<https://en.wikipedia.org/wiki/Palette_(computing)>) used to tint sprites. To be specific:
+
+- An array of 256 8-bit RGBA color values is appended at the end of any (modern) [SPR](/file-formats/spr) sprite - the "default palette"
+- All standalone PAL files found in the game client are using exactly the same format, which makes it easy to recolor sprites
+- The client can swap any one of them in to replace the default palette, with certain palettes matching specific sprites
+
+All the same limitations apply to the default and alternative palettes - that is to say, transparency isn't supported.
+
+## Alpha Channel
+
+Transparency is determined for each color according to its RGBA values, after loading the palette:
+
+- The color stored at palette index 0 is considered the transparent background color - usually red, green, or magenta
+- Colors that are "close" to the transparency color might also be rendered transparent (warning: unverified claim)
+- If a palette contains alpha values, they appear to be ignored in favor of the actual transparency color
+
+The exact behavior requires some verification still, but a possible approach was described [here](https://github.com/rdw-archive/RagnarokFileFormats/blob/master/PAL.MD) (might be incorrect, though).
+
+## Layout
+
+See the `ColorPalette` field in the [SPR layout table](/file-formats/spr#layout). Any SPR file above version `1.1` includes a default palette (i.e., all of them do).