HI! I want to limit the format of the text th...

[Guillermo_Osina]

HI! I want to limit the format of the text that can be entered for a field, as example: only can enter text beggining with prefix EXT- or 2.0- and 3 digits after it, example:

2.0-052 EXT-001

Which formula can i use to avoid to enter already existing values in the column?

Thanks!

[Aleksi_Alkio]

#1 - You need to create a validation rule and it could be something like…

AND( LEN([_THIS])=7, OR( LEFT([_THIS],4)=“2.0-”, LEFT([_THIS],4)=“EXT-”) )

#2 - You can avoid duplicate value with the formula…

IF([_THIS]=LOOKUP([_THISROW].[KeyColumn],Table,KeyColumn,ColumnA),

TRUE,

NOT(IN([_THIS],Table[ColumnA])))