Using marks
http://vim.wikia.com/wiki/Using_marks

1. There is no visible indication of where marks are set.
2. Each file has a set of marks identified by lowercase letters (a-z).
3. In addition there is a global set of marks identified by uppercase letters (A-Z) that identify a position within a particular file.
For example, you may be editing ten files. Each file could have mark a, but only one file can have mark A.

4. Set mark
ma: set mark a at current cursor location

5. Jump to mark
'a: jump to line of mark a (first non-blank character in line)
`a: jump to position (line and column) of mark a

6. Delete line as per mark
d'a: delete from current line to line of mark a

7. List marks
:marks: list all the current marks
:marks aB: list marks a, B

8. Delete marks
:delmarks a
:delmarks a-d
:delmarks aA
:delmarks! -> delete all lowercase marks for the current buffer (a-z)