The records from these indexes were obtained from the Texas State Records
ERRORS ON THE INDEX FILES
The Bureau of Vital Statistics recognizes that there may be missing data, misreported data, or data entry errors. Users of the indexes may discover an error such as a misspelling of a name or an incorrect date.
The Bureau of Vital Statistics indexes are static and cannot be altered. However, if you are concerned that the original certificate is in error, you may file an amendment to the certificate with the correct information.
IF THE BIRTH RECORD SAYS "DO NOT ISSUE" IN THE FATHER'S NAME FIELD
In the past, when a person died, the father's name field on the electronic birth record was changed to "DO NOT ISSUE". This was a method that was established as a flag to BVS personnel that they should not issue a certified copy of this birth certificate to anyone claiming to be the deceased.
You can find more information at the Texas Vital Statistics Unit