The anti-abortion group Youth Defence actively campaigns on the issue of abortion in schools on an ongoing basis.
According to its website, Youth Defence sends pro-life materials to every school in Ireland, including DVDs, a "wall poster which brings students through the stages of development within the womb", booklets and a "fun quiz".
The group also sends speakers into schools and claims that "at times it is difficult to keep up with demand".
The main Pro-Choice group, Together For Yes, says it does not campaign in schools.
The Irish Family Planning Association (IFPA), which has a Pro-Choice ethos, gives talks in schools about sexual health as part of RSE. The five-hour programme covers topics such as reproduction, consent, healthy relationships and contraception, but not abortion.
The IFPA gives information about non-directive crisis pregnancy agencies.
To be eligible to vote, students who are 18 or over by referendum day, May 25, have to register by May 8.
To check if you are on the register, see checktheregister.ie.
To register, voters will need to fill in the RFA2 form at checktheregister.ie/appforms/RFA2_English_Form.pdf.
The form should be signed and witnessed at a garda station and sent either by post or by hand to a city or county council.