Meaning of "natural alignment" is unclear

[RalfJung]

The CABI documentation uses the term "natural alignment" of a type without defining its meaning. Talking to different people I have encountered two common meanings of this word:

• it refers to the default alignment the type has without adding any alignment-modifying attributes
• it means the alignment equals the size of the type

For the sake of clarity of this spec, it would be good to spell out exactly which meaning is intended here.