In the help of less in bash, it says tha we can mark a position with m<letter>, then go to the mark with '<letter>. it seems that the m<letter> doesn't work at all, suppose i type ma, while if i type ' , a line "go to mark: " shows at the bottem, then i type a, it says no such mark, can anybody tell me why. Thx for answering...

I found out the answer by myself, it works, as long as you don't use it in 'h'...