I will publish a conference paper and as I'm a PhD student the committee asked "If the corresponding author is a PhD/MSc student, he/she also should send a Publication Approval Letter from his/her supervisor".
What does it mean? What is a Publication Approval Letter?
In some fields journals and conferences may want to know that a student is "authorized" in some way to publish. This might especially be true if your advisor is a co-author, but not the corresponding author. They just want confirmation. The letter should come from your advisor and can be short and to the point.
Judging from your comment, this publication approval letter is supposed to show that your supervisor approves of the publication (i.e. that your supervisor is aware of the publication and has no problems with you publishing it). You'll have to ask your supervisor for it.
