Mandailing

I first heard of this word as Mendaling or Mendeleng. Later I heard it as Mandailing from a surveyor, Assoc Prof Sr Azlan Raofuddin at HBP (Housing, Building and Planning) in USM, Penang. His mother is a Mandailing lady.

What is Mandailing?

How are they different or similar?

http://www.mandailing.org/Eng/contents.html
http://www.mandailing.org/Eng/links.html