There is a little consistency required in the WBS coding mask here. Let's say the coding mask is AB/XXXX-0000-XXX-0000.
The project definition is AB/PQRS-0001. Here the 1st level WBS element is also AB/PQRS-0001. Then when I'm going to create 2nd level WBS by drag & drop method, the system automatically creates WBS as AB/PQRS-0001-1 rather than AB/PQRS-0001-001 as the last part is alphanumeric. So is there any possibility that system will throw error if you do not enter 3 characters in the last mentioned level.