cross references in the catalog link subjects

[VicNicSor]

coordinate
adj
1) equal in rank or importance
cross references in the catalog link subjects that may be coordinate.
OED

I've lost myself in the sentence. Is 'cross references' a noun or 'cross' is a verb? Does "catalog link" act as an adjective modifying the word "subjects"?Thank you.

 

[pob14]

The verb is "link."

Cross references (that are) in the catalog . . . .
. . . link subjects . . .
. . . that may be coordinate.

Edit: It would have helped if "Cross-references" had been hyphenated.

 

[Egmont]

"Cross references" is a noun. "Link" is a verb. The cross references [which ones? The ones in the catalog] link two things to each other: specifically, related subjects.

Added in edit: I agree with the cross-posted suggestion to use a hyphen in "cross-reference." I didn't use hyphens in my post because the original didn't, not because they shouldn't be there.

 

[VicNicSor]

Thank you all.