60638 is a postalcode and its consensus geometry is derived from uszcta.
{"mz:is_ceased":0,"geom:latitude":41.781433,"wof:name":"60638","counts:names_total":0,"wof:placetype":"postalcode","mz:is_current":1,"wof:hierarchy":[{"continent_id":102191575,"country_id":85633793,"county_id":102084317,"localadmin_id":404496273,"locality_id":85940195,"postalcode_id":554783419,"region_id":85688697}],"mz:is_deprecated":0,"lbl:latitude":41.78143,"mz:postal_locality_alt":["Bedford Park"],"geom:area":0.003115,"geom:longitude":-87.770519,"wof:id":554783419,"counts:concordances_total":1,"geom:type":"Polygon","wof:lastmodified":1611183894,"wof:belongsto":[102191575,85633793,102084317,404496273,85940195,85688697],"wof:concordances":{"gp:id":"12784290"},"wof:repo":"whosonfirst-data-postalcode-us","src:geom":"uszcta","wof:country":"US","counts:names_preferred":0,"geom:area_square_m":2.8724502313637E7,"wof:tags":[],"counts:names_variant":0,"wof:breaches":[],"edtf:inception":"uuuu","iso:country":"US","counts:names_languages":0,"geom:bbox":"-87.804781,41.751781,-87.739368,41.816482","wof:superseded_by":[],"wof:supersedes":[],"lbl:longitude":-87.770521,"wof:geomhash":"0c4449ce1e826721bc1775764517ad61","wof:parent_id":85940195,"wof:placetype_names":["postalcode"],"mz:hierarchy_label":1,"wof:placetype_id":470996387,"edtf:cessation":"uuuu","mz:postal_locality":"Chicago"}