I just wrote a reference for one of my students to study at York University, and the message that came back was:
Thank you for taking the time to upload a reference for Ms Xxx Xxx in connection with their application for the MSc in Forensic Speech Science.
(where I have blanked out the name to maintain anonymity).
It is interesting to see that the University uses 'their', even though the gender of the applicant is known to be female (note the use of 'Ms').
I find it encouraging that 'they' and 'their' are becoming increasingly acceptable for singular referents. It makes things so much easier than having to write 'his or her' or something clumsy like that.