And does anyone know what the caret (^) symbol means in formula fields?

Happy to share my understanding though I don't have a definitive answer. It seems to be used when a join has multiple potential types. For example, a transaction dataset can join to multiple entity record types, i.e. customer, employee, partner, vendor, etc. If the formula was pulling the customer name through a join then I would expect to see

entity^customer.companyname

. I'm not sure the caret symbol has inherit meaning but it's helpful in noting what type of record is being joined to.

entity

part should be the field on the record your joining from

customer

is the record type being joined to,

companyname

is the field your pulling from the joined record. That would be my understanding.

It's explained here