0 abbreviation for buy-to-let :
1 abbreviation for below the line: used to describe discussions or replies from readers that are published below an internet article, blog, etc.:
2 → below-the-line
mortgage lenders specializing in BTL
Love them or hate them, BTL comments have changed journalism.
Some of the btl commenters were really vicious.
As many people have pointed out BTL, there are factual errors in this column.
There's quite an interesting discussion BTL.
