Learning to spell with Obamacare: Are policies being canceled, or are they being cancelled?

The New York Times put up the headline:

Obama Moves to Avert Cancellation of Insurance

And in the first paragraph reported:

[Obama] announced a policy reversal that would allow insurance companies to temporarily keep people on health plans that were to be canceled under the new law because they did not meet minimum standards. [emphasis added]

Setting aside the policy for a moment, what is going on here? Why is "cancellation" (two l's) correct in the headline, while "canceled" (single l) is correct in the first paragraph? When does the l get doubled, and when does it not get doubled?

It turns out that health care is not the only thing done differently in the UK vs. the US. There is a somewhat obscure spelling "rule" (caveat: there are no completely reliable spelling rules in English) exercised in US English that will help you with seemingly incongruous spellings like "traveled" and "referred."

This is covered over at English-Zone.com:

Rule 1:  Words ending with a Consonant-Vowel-Consonant  Pattern

One-syllable words:
ED =  If the word ends in a CVC pattern, it gets a double consonant + ED.     * note
ING =  If the word ends in a CVC pattern, it gets a double consonant + ING. * note

Examples:

ED =   RUB > rubbed, STOP > stopped

ING = HOP > hopping,  SIT > sitting

*note: Words ending in w,x,y,z do not follow this rule, simply add ED, or ING Examples: snow > snowed, box > boxing, play > playing

Two-syllable words:
ED =  If the stress is on the first syllable, the word only gets one consonant + ED.
ING = If the stress is on the first syllable, the word only gets one consonant + ING.

Examples:

visit > visited, open > opened

happen > happening,  enter > entering

ED =  If the stress is on the second syllable, the word gets a double consonant + ED.
ING = If the stress is on the second syllable, the word gets a double consonant  + ING.

Examples:

refer > referred,     admit > admitted

begin > beginning, permit > permitting

I will expand on that explanation a bit. It is not just two-syllable words and "ed" and "ing" suffixes that are affected. In fact, any multi-syllable word and any suffix that begins with a vowel are affected. If the final three letters are Consonant-Vowel-Consonant (CVC) and the accent is on the final syllable, double the consonant if the suffix begins with a vowel.

Note that "cancel" follows that Consonant-Vowel-Consonant (CVC) pattern, and it is a two-syllable word. Now note what happens if the word ending to add is "ation" vs. "ed":

cancel + ation = "cancellation"
cancel + ed = "canceled"

It is the accent that determines the spelling. The two words are pronounced "canCELLation" and "CANceled," so as the accent moves, the spelling changes.

There are other similar cases, such as "referred" and "reference"; or "conferred" and "conference." If you know where the accent falls, you'll be able to add the suffix correctly.

Keep in mind this rule works for US English, but in UK English the doubling of the consonant is far more common, as in "travelling" and "modelling."

While you're at it, keep in mind that in the US both spellings are acceptable for some words ("cancelling" and "modelling" both make it past my spelling checker); but if you stick to the basic rule, you'll be fine.