Trouble with two table references - same settings, different results.

I have a a Table called 'Pages' and I want to use a code for the year and month on entries to that Table.

 

I have created two further Tables, 'Years' and 'Months'.

 

For historical reasons the dates need recorded as a code so my 'Years' Table is along the lines of

 

Year      Year Code

2000     AA

2001     AB

2002     AC

 

And the 'Months' Table

 

Month     Month Code

January   A

February B

March     C

 

and so on.

 

In a 'Pages' entry I want to choose the Year and Month and have those displayed in my code. So rather than have 2002 February I want AC B.

 

I have created References: From Pages to Years (N:1) and that works. I click in my 'Year Code' field, it brings up my Years Table and I select 2002. I now see "AC". Perfect. Now, same setup using From Pages to Months (N:1). I click, select February and my field then shows "February B".

 

So the Years Table correctly gets me "AC" not "2002 AC" while the Months Table gives me "February B" rather than the "B" I want.

 

Now I think somewhere in the "Edit Columns" I can say which fields should show, and I think I've done that elsewhere. However, I have edited anything for Years. So why does Months show the whole Table entry while Years just gives me the answer I want?

 

Thanks.