Where is the customization for this field from the Warranty and Repairs SuiteApp?

I'm trying to input a bunch of warranties into NetSuite via CSV.

It's returning an error saying that the Reference Serial/Lot No. field (custrecord_wrm_reg_ref_seriallot) only accepts numbers and hyphens. This is not the same functionality as regular serial and lot numbers, no? I already have the items I'm trying to create these warranty records for in my system and their serial numbers include hashtags and spaces.

I can't seem to find the location of the field anywhere in my customization, unlike almost all of the other fields, records and lists included in the SuiteApp.

Can anyone help me find where the customization for this field is located so that hopefully I can change the parameters it accepts? Or otherwise suggest a workaround. There's no mention of it in the bundle details either and when I enter one manually the error appears as a popup when attempting to save the record, so perhaps it's inside one of the scripts? But those are locked/hidden…