Hull (Options, Futures, and Other Derivatives) calls that the "type" of the option (emphasis added):
there are two types of options. A call option... A put option...
So does NASDAQ:
Option Types: Calls & Puts
I have seen
optionType used in many places to identify if the option is a call or put. I certainly wouldn't complain about
PutCall or some other more specific name, but
Type should not conflict with other attributes.
OptionType seems too vague. It could refer to the contract size or the type of underlying security (stock, bond, index).
I can't see how the contract size could be considered a "type". I would consider stock, bonds, index, etc. the type of the underlying, which could be an attribute on the option, but would be more appropriate in a separate entity that represents the underlying instrument.
*To be fair, there are also sites that call American and European the "type" of the option, but I have always seen that called the
exerciseType to disambiguate that from put/call.