Seem Yahoo will add some new operator soon ! Or may be they are use internally use to help detect some page/bug/spammer ?
Here the new operator :
TITLEWORDS (term1 term2)
This have to be uppercase. The main difference from intitle: is the number of words use. With the intitle: you'll have a lot of time only one or two words to be really in the intitle: searches. But when you're using TITLEWORDS all the words are include in the title.