Should the words inside a set of parentheses be capitalised?

For example:

... usually read for personal enjoyment (Recreation) or ...

or

... usually read for personal enjoyment (recreation) or ...


You only need capitalize a parenthesis if it is a complete sentence terminating with a period or full stop. Thus:

... usually read for personal enjoyment (recreation) or ...


There is no need to capitalize words in parentheses.

Where we were going (it was not open for discussion) was kept secret from us.