Trade: err, no, there's no "upper 15 bits" in a 16bit MeshAttribute.

And same in case of SceneField. What a weird wording choice.

src/Magnum/Trade/MeshData.h

@@ -51,7 +51,7 @@ namespace Implementation {
 See @ref MeshData for more information.
 
 Apart from the builtin attribute names it's possible to have custom ones,
-which use the upper 15 bits of the enum range. Those are detected via
+which use the upper half of the enum range. Those are detected via
 @ref isMeshAttributeCustom() and can be converted to and from a numeric
 identifier using @ref meshAttributeCustom(MeshAttribute) and
 @ref meshAttributeCustom(UnsignedShort). Unlike the builtin ones, these can

src/Magnum/Trade/SceneData.h

@@ -96,7 +96,7 @@ namespace Implementation {
 See @ref SceneData for more information.
 
 Apart from the builtin field names it's possible to have custom ones, which use
-the upper 31 bits of the enum range. While it's unlikely to have billions of
+the upper half of the enum range. While it's unlikely to have billions of
 custom fields, the enum intentionally reserves a full 31-bit range to avoid the
 need to remap field identifiers coming from 3rd party ECS frameworks, for
 example.