Have this 1988 error cud that looks like a canal under "IN GOD" This is also a Wide AM 1988 but I haven't gotten my USB microscope, can't tell if it's the right FG (designer).
If you are talking about the raised area that runs through the lettering that is not a cud. that is caused by die wear and is not considered an error
As said, this is a deteriorated die issue, not an error. I just finished up an original roll of these and every one of them had this issue. Must have been a tough year. Plus from a die that should have been retired.