Registration vs Tail Number - What to put?

[Cloudster 16]

When adding a new aircraft in PFPX it asks for Registration and Tail Number field. Aren't these both the same thing? I'm confused on what to put.

 

For example let's take this plane Thomas Cook, it has painted on the side rear panel OO-TCY, now if this is the Registration, then what's the Tail number?

 

I'm trying to find the correct information using these charts:

 

https://www.planespotters.net/airframe/Airbus/A320/1968/OO-TCV-Thomas-Cook-Airlines-Belgium

https://www.flightradar24.com/data/aircraft/oo-tcv

http://www.airfleets.net/ficheapp/plane-a320-1968.htm

http://cdn.airplane-pictures.net/images/uploaded-images/2015/4/15/548705.jpg

 

[bcars 23]

The registration number is what is on file with that country's regulatory agency.

In the US  all aircraft have an 'N'  prefix (also referred to as the N-number). As a new plane is registered ( or if one is sold and re-registered to a new owner) it will be assigned a registration number.   For example,  a United Airlines 737 might get a registration number of N13750.

 

In turn, the airlines might assign an internal  fleet number or tail number  to designate that aircraft in a series of aircraft.  United tries to group the aircraft by type ( eg 737,  757, etc)  So they may assign an internal number (fleet number/nose number)  to be used for internal references.  United ( as do others)  will paint this number on the nose or tail.  Using the above example of the United 737, the registration number is  N13750. It has a Nose / Tail/ Fleet number of 750.  ( not necessarily a coincidence that the last 3 numbers of the registration number were used as the fleet number.)    A series,  say 201-280 ,  may represent 737-600 in a specific configuration ( seat arrangment etc). This can then make it easier to group the aircraft for scheduling purposes and substitution when a replacement aircraft is needed on a given route segment.

This Fleet / Tail Number appears on the OFP for most airlines.

 

PFPX provides both fields  so  that the OFP can include either or both numbers  as desired.