do you have a list of Market ID's? if so, create 1 column with the market id, and one with the abbreviation eg
[TABLE="width: 500"]
<tbody>[TR]
[TD]IL[/TD]
[TD]Market ID1[/TD]
[/TR]
[TR]
[TD]AC[/TD]
[TD]Market ID2[/TD]
[/TR]
[TR]
[TD]BK[/TD]
[TD]Market ID3[/TD]
[/TR]
[TR]
[TD]DG[/TD]
[TD]Market ID 4[/TD]
[/TR]
</tbody>[/TABLE]
Name that range as per last email, with any name you like eg(tolookup)
Then in the sheet you have the sites ID's in:
[TABLE="width: 500"]
<tbody>[TR]
[TD]IL12345[/TD]
[TD]some info[/TD]
[TD]some info[/TD]
[TD]=vlookup(left(a1,2),tolookup,2,false)[/TD]
[/TR]
[TR]
[TD]AC4567[/TD]
[TD]some info[/TD]
[TD]some info[/TD]
[TD]=vlookup(left(a2,2),tolookup,2,false)[/TD]
[/TR]
[TR]
[TD]BK9876[/TD]
[TD]some info[/TD]
[TD]some info[/TD]
[TD]=vlookup(left(a3,2),tolookup,2,false)[/TD]
[/TR]
[TR]
[TD]DG7548[/TD]
[TD]some info[/TD]
[TD]some info[/TD]
[TD]=vlookup(left(a4,2),tolookup,2,false)[/TD]
[/TR]
</tbody>[/TABLE]
you could prepopulate the formula down, but in its current form would display N/a it there is no value in the site id cell. you can fix this by changing the formula to =ifna(vlookup(left(a1,2),tolookup,2,false),"")