From 9669e46ff83fdaac0d1c09d21473ffec76f8b604 Mon Sep 17 00:00:00 2001
From: VorTechnix <45538536+VorTechnix@users.noreply.github.com>
Date: Sun, 1 Aug 2021 10:37:13 -0700
Subject: [PATCH] added conventions header and DIR details

---
 Chat-Command-Reference.md | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/Chat-Command-Reference.md b/Chat-Command-Reference.md
index 3cde615..2edbdcd 100644
--- a/Chat-Command-Reference.md
+++ b/Chat-Command-Reference.md
@@ -11,6 +11,22 @@ Other useful links:
 
 **Note:** If anything in this reference isn't clear, that's a bug. Please [open an issue](https://github.com/sbrl/Minetest-WorldEditAdditions/issues/new) (or even better a PR improving it) to let me know precisely which bit you don't understand and why.
 
+## Conventions
+
+Conventions for command syntax.
+
+### DIR
+WorldEditAdditions uses the `DIR` system in some of its selection modifier commands. `Dir`s are relative to the axis the player is facing and are defined as follows:
+
+|Name|Definition|
+|---|---|
+`front`|The horizontal axis (X or Z) which the player is mostly facing toward and the multiplier (1 or -1) corresponding to whether the value of the player's position vector corresponding to that axis would increase or decrease if they moved in the direction they are facing.
+`back`|Same axis as `front` but the multiplier is inverted (m * -1).
+`left`|The horizontal axis (X or Z) perpendicular to the player with the opposite multiplier to `front` if the front axis is Z or the same multiplier as `front` if the front axis is X.
+`right`|Same axis as `left` but the multiplier is inverted (m * -1).
+`up`|The Y axis with the multiplier 1.
+`down`|The Y axis with the multiplier -1.
+
 
 ## `//floodfill [<replace_node> [<radius>]]`
 Floods all connected nodes of the same type starting at _pos1_ with <replace_node> (which defaults to `water_source`), in a sphere with a radius of <radius> (which defaults to 50).
@@ -373,6 +389,7 @@ The above functions just like `//replace` - nothing special going on here. It re
 
 
 
+
 Let's make it more interesting:
 
 ```weacmd
@@ -709,6 +726,7 @@ Short for _select point cloud_. Sets pos1 and pos2 to include the nodes you punc
 ```
 
 
+
 ## `//scentre`
 Short for _select center_. Sets pos1 and pos2 to the centre point(s) of the current selection area. 1, 2, 4 or 8 nodes may be selected depending on what parts of the original selection are even in distance. Implementation thanks to @VorTechnix.