B767 pilot reported landing at an airport only allowed to be an alternate per the company op spec.

Attributes
ACN	1605134
Time
Date	201812
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Plan	IFR
Person 1
Function	Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Events
Anomaly	Deviation - Procedural Published Material / Policy

Narrative:

Flight was awarded in the bid and flown as scheduled. After completing pairing no indication of any possible discrepancies/violation of a far or company operational specs was not made known until suggested by an as soon as possible member via email to suggest the filing of this as soon as possible. This suggestion was received today. The event is noted as operating an aircraft per C070 with an incorrect airport status. To my understanding based on the current suggestion a B767 was only authorized to operate into ZZZ for alternate reasons and not scheduled. No further events occurred.

Original NASA ASRS Text

Title: B767 pilot reported landing at an airport only allowed to be an alternate per the company Op Spec.

Narrative: Flight was awarded in the bid and flown as scheduled. After completing pairing no indication of any possible discrepancies/violation of a FAR or Company Operational Specs was not made known until suggested by an ASAP member via email to suggest the filing of this ASAP. This suggestion was received today. The event is noted as operating an aircraft per C070 with an incorrect airport status. To my understanding based on the current suggestion a B767 was only authorized to operate into ZZZ for alternate reasons and not scheduled. No further events occurred.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.