"Hide filename" not available under encrypt 7zip format

[Morph]

In the past I used 7ZIP and was able to hide filenames during encryption of an archive. I bought PA (13.02.02 09/2012) believing that was also possible, reading the manual pages and online help. But when I select Encrypt, and then 7ZIP format, I cannot see "hide filename" as an option. It only exists if you choose PAE as an output format.

Bug? Its very helpful to hide the filenames as it clearly makes it harder to decrypt if you have no clue as to possible contents of each sub-file.

Mike
BTW - the captcha requirement on every post ... a bit excessive, and some of them are pretty hard to read as a human!