priority of execution

[Ray Andrews <rayandrews@eastlink.ca>]

So far I'm aware of these categories of actionable entities:

alias, autoload, builtin, function, executable script, binary.

Any others?  Or any other discriminations possible within those 
categories?  IOW, what's the total list of species that whence might 
report?  And when I have a complete list of such species, what's their 
precedence?  I believe aliases always come first but in case of name 
conflicts I'd like to be sure who has first go. And:

$ whence -v declare
declare is a reserved word

$ whence -av declare
declare is a reserved word
declare is a shell builtin

... isn't the main point that it's a builtin and thus it's a reserved 
word automatically?  I'm not sure that's correct, but it seems to me 
that the name of a builtin must be protected so I'd expect:

$ whence -v declare
declare is a shell builtin   # Which is what I really want to know, and 
that it's reserved is redundant.