diff --git a/doc/main.md b/doc/main.md
index 9d9c737..1157c4e 100644
--- a/doc/main.md
+++ b/doc/main.md
@@ -15,6 +15,8 @@ Additionaly, `TEXTURE2` lump **must not** exist!
 
 Refer to [textures](textures.md) for workaround.
 
+NOTE: If you have issues with certain map editors you can, for development, split ACE Engine and your stuff into two different WAD files and merge those just before final release.
+
 ## TOC
 
 - [good to know](stuff.md)
diff --git a/doc/stuff.md b/doc/stuff.md
index 69a3391..83a77f9 100644
--- a/doc/stuff.md
+++ b/doc/stuff.md
@@ -3,6 +3,14 @@
 ACE Engine is a hack for DOS Doom so i has various workrounds, speed optimizations and stuff.  
 Here are some recommended things and good tips.
 
+## IWAD
+
+ACE Engine **can** be used in IWAD! If used this way, users won't be presented with `modified game` warning.  
+IWAD othewise must have all lumps required by `doom2.exe` present. (except wall and flat textures)  
+The only important thing is to place ACE Engine lumps **last** in a wad file.
+
+TIP: If you name your wad file `doom2f.wad`, it will take priority over normal IWAD.
+
 ## Precalculation
 
 Since palette color matching on 486 hardware is slow, some tables are better precalculated.