Spelling of "cachable"

John Franks asks:

    Is there a consensus on the spelling of cachable/cacheable?  Both
    versions are used in draft 08.  Is there an authority we can appeal
    to?

I did some research on this when I was writing my dissertation, about
10 years ago.  I don't think I actually found a dictionary entry
that listed either form explicitly, but I remember finding an
unabridged dictionary that gave standard rules for spelling such
forms of verbs, and it definitely pointed to "cachable", not
"cacheable."  The unabridged dictionary I have at hand ("Webster's
Third New International Dictionary", Pub. Merriam-Webster, 1961)
says (p. 22a, "Spelling", rule 1.7) "words ending in silent -e
drop the vowel before a suffixal vowel."  However, under exception
(6), "although final -e regularly drops before the suffix -able,
some adjectives in -able have alternatives retaining the -e ...
British usage is more inclined than U.S. usage to retain the
form with e; recent or nonce formations, especially from
polysyllable base words, usually appear without the e ...".

Modern lexicographers usually resolve these issues by looking at
a large "corpus" of texts, and seeing what people actually use.
The low-fidelity substitute for this kind of research is to use
AltaVista (or some other search engine) to see what the Web uses.
AltaVista says "Word count: cachable: 360; cacheable: 1224",
which contradicts my dictionary research.  Hmm.

I think the key here is that British usage might tend towards
"cacheable", although my OED is at home so I can't check that
while I write this.

However: in draft -08 (and in RFC2068), "cacheable" appears only
once, and "cachable" appears dozens of times.  I vote to stick
with "cachable."

-Jeff

P.S.: Remember the routing-protocol wars of a few years back?
The OSI routing protocol was formally called 
	"Information processing systems -- Telecommunications and
	information exchange between systems -- Intermediate system to
	Intermediate system Intra-Domain routeing exchange protocol for
	use in conjunction with the protocol for providing the
	connectionless-mode network service (ISO 8473)", ISO 10589,
	1990.
ISO apparently required that English-language standards be spelled
according to the OED, which prefers "routeing" to "routing".  That
looks really weird to me.