The Bill type is officially a four-digit field, but historically users have known it as a three-digit field, hence the usage of the bill type '711'. If however you print a UB-04 for a claim with a 711 bill type (a new claim), you will see it prints 0711 in the top right bill type field.
There is a similar thing that goes on with revenue codes, they are officially also four-digit and get a leading 0.
Now, the less obvious thing about bill types is that the first three digits are the actual bill type, so 071 or 71
The last field is the 'claim edit indicator': 1 for new, 7 for corrected. So if you save the claim and it prompts if you want to mark it as corrected, your answer to that question will determine if the claim edit indicator is set to 1 or 7.