I've been trying to figure out what the rules are with student tickets bought online. The irishrail website doesn't mention any special rules governing student tickets, but the RUI information mentions that they are valid on any service that day
http://www.railusers.ie/passenger_in...ts.php#student
I sent an email asking how flexible the student fares were and the most they would tell me is:
"When booking online you have select dates and times regardless of whether its student or adult fare,"
Which doesn't really answer my question (implies the opposite to what's on the RUI website, if anything).
A few of my friends have heard similar things before (it would explain student fares sometimes being more expensive), but there's no official information to be found.
They should really add a line to
http://www.irishrail.ie/index.jsp?p=141&n=205 if students have no surcharge.