For ePub 3.0 the head element is shown at
http://idpf.org/epub/30/spec/epub30-...-oeb-head-foot
the oeb-page-head has been around since before ePub (OEB version 1) and was actually implemented by some systems. You can use the page as an example to build an ePub to be checked in the iPad. Note the iPad iBooks application does not claim to be ePub 3 compatible, only HTML5 which is only a portion of ePub 3. However oeb-page-head is also in ePub 2.1 so there is a chance. I have not tried it myself. The example I referenced shows how to make the header dynamic.
Saying your clients will be using an iPad or Android means nothing. You will need to determine the exact app that will be used to display your data. In order to test what your build you should also determine if there is an application on the build platform that will display this data.
Dale