Some little known wire signals
1 - Wait a moment
25 - Busy on another wire
2 - Important business
26 - Put on ground wire
3 - What time is it?
27 - Priority, very important
4 - Where shall I go ahead?
28 - Do you get my writing?
5 - Have you business for me? 29 - Private, deliver in sealed envelope.
6 - I am ready 30 - No more-end
7 - Are you ready? 31 - Form 31 train order
8 - Close your key; circuit is busy
32 - I understand that I am to .........
9 - Close your key for priority business (wire chief, dspr, etc.)
33 - Car report (Also, answer is paid for)
10 - Keep this circuit closed
34 - Message for all officers
12 - Do you understand?
35 - You may use my signal to answer this
13 - I understand
37 - Diversion (Also, inform all interested)
14 - What is the weather?
39 - Important, with priority on through wire.
(Also, sleep-car report)
15 - For you and other to copy
44 - Answer promptly by wire
17 - Lightning here
73* - Best regards
18 - What is the trouble?
88* - Love and kisses
19 - Form 19 train order 91 - Superintendent's signal
21 - Stop for meal
92 - Deliver promptly
22 - Wire test
93 - Vice President & general manager signals
23 - All copy
95 - President's signal
24 - Repeat this back
134 - Who is at the key?
*The well-known ones. Note!!! It is seven three; not seventy-three, not seventy-threes or seven threes! It is already plural!
There are now some weird  usages in e-mails, including '73 and 73'. Huh?