General Acronyms

a.k.a.
also known as
ABS
Automatic Block Signalling
acc.
accession
c
circa (suffix to numeric date)
ca.
circa (prefix)
col.
collection
CTC
Centralized Traffic Control
ETT
Employee Time Table
ft.
foot or feet
ibid
in the same place
in.
inch or inches
n.a.
not applicable
n.d.
no date
n.p.
no publisher
no.
number
nos.
numbers
op. cit.
[L opere citato] in the work cited
p.
page
pp.
pages
PTT
Public Time Table
rr
railroad
ry
railway
TT
Time Table