Change the Network Number field in Analytics to use a semicolon between subfields in addition to fields.
The Network Number field in Analytics includes a number of fields, including 035$a and $z, 019 $a and $z, and some 7xx linking fields. The documentation says the delimiter is "; ".
What actually happens is that the delimiter is present only between fields, not between numbers in repeatable subfields in the same field. If an 035 contains one $a and three $z subfields, there will not be a semicolon delimiter between them, only a space. This makes it difficult to parse out individual fields, and not possible to find erroneous numbers with a space in the subfield.
Please change the behavior of this field to use the documented delimiter between every number, whether is it on a separate field or not.