diff --git a/code/__HELPERS/icons.dm b/code/__HELPERS/icons.dm
index 7b71eea0204..1944cff9c61 100644
--- a/code/__HELPERS/icons.dm
+++ b/code/__HELPERS/icons.dm
@@ -706,7 +706,12 @@ world
 		((hi3 >= 65 ? hi3-55 : hi3-48)<<4) | (lo3 >= 65 ? lo3-55 : lo3-48),
 		((hi4 >= 65 ? hi4-55 : hi4-48)<<4) | (lo4 >= 65 ? lo4-55 : lo4-48))
 
-// Creates a single icon from a given /atom or /image.  Only the first argument is required.
+/// Create a single [/icon] from a given [/atom] or [/image].
+///
+/// Very low-performance. Should usually only be used for HTML, where BYOND's
+/// appearance system (overlays/underlays, etc.) is not available.
+///
+/// Only the first argument is required.
 /proc/getFlatIcon(image/A, defdir, deficon, defstate, defblend, start = TRUE, no_anim = FALSE)
 	//Define... defines.
 	var/static/icon/flat_template = icon('icons/effects/effects.dmi', "nothing")