--- a/mojoshader.h	Wed Jun 24 14:19:28 2020 -0400
+++ b/mojoshader.h	Wed Jun 24 14:19:46 2020 -0400
@@ -236,19 +236,19 @@
 typedef enum
 {
     MOJOSHADER_USAGE_UNKNOWN = -1,  /* housekeeping value; never returned. */
-    MOJOSHADER_USAGE_POSITION,
-    MOJOSHADER_USAGE_BLENDWEIGHT,
-    MOJOSHADER_USAGE_BLENDINDICES,
-    MOJOSHADER_USAGE_NORMAL,
-    MOJOSHADER_USAGE_POINTSIZE,
-    MOJOSHADER_USAGE_TEXCOORD,
-    MOJOSHADER_USAGE_TANGENT,
-    MOJOSHADER_USAGE_BINORMAL,
-    MOJOSHADER_USAGE_TESSFACTOR,
-    MOJOSHADER_USAGE_POSITIONT,
-    MOJOSHADER_USAGE_COLOR,
-    MOJOSHADER_USAGE_FOG,
-    MOJOSHADER_USAGE_DEPTH,
+    MOJOSHADER_USAGE_POSITION,      /* 0-15 for Vertex, 1-15 for Pixel */
+    MOJOSHADER_USAGE_BLENDWEIGHT,   /* 0-15 */
+    MOJOSHADER_USAGE_BLENDINDICES,  /* 0-15 */
+    MOJOSHADER_USAGE_NORMAL,        /* 0-15 */
+    MOJOSHADER_USAGE_POINTSIZE,     /* 0-15 */
+    MOJOSHADER_USAGE_TEXCOORD,      /* 0-15 */
+    MOJOSHADER_USAGE_TANGENT,       /* 0-15 */
+    MOJOSHADER_USAGE_BINORMAL,      /* 0-15 */
+    MOJOSHADER_USAGE_TESSFACTOR,    /* 0 only */
+    MOJOSHADER_USAGE_POSITIONT,     /* 0-15 for Vertex, 1-15 for Pixel */
+    MOJOSHADER_USAGE_COLOR,         /* 0-15 but depends on MRT support */
+    MOJOSHADER_USAGE_FOG,           /* 0-15 */
+    MOJOSHADER_USAGE_DEPTH,         /* 0-15 */
     MOJOSHADER_USAGE_SAMPLE,
     MOJOSHADER_USAGE_TOTAL   /* housekeeping value; never returned. */
 } MOJOSHADER_usage;