I'm using server side validation, the php variety. I don't see a conditional option. The only kind of conditional I see is "like entry."
It's certainly possible that setting up conditional validation where if, for instance, a checkbox is selected then a particular text input must have data, is available but I just don't see it.
I've got
Alphanumeric
CC number
Date/time
Email address
entry length
File extension
like entry
number
phone number
regular expression
required/not blank/selection made
restrict content
SS number
url
zip code
I must not be seeing something right in front of my face.
