Post file (6)
I believe the answer is:
column
This clue is a double definition.
'post' is the first definition.
(I've seen this before)
'file' is the second definition.
(column is a kind of file)
(Other definitions for column that I've seen before include "Linear display, of numbers say" , "Upright pillar and newsprint division" , "Tall cylindrical vertical upright" , "Pillar - newspaper slot" , "Newspaper article giving an opinion" .)