There are a wide variety of reasons why you may be denied boarding. I described some of the alleged security reasons here with references: Physical appearance and clothing, do they affect the passenger's chances of getting on the plane?

In the example in question, the reason was not security (or a pretence at security), it was (allegedly) decency. From the article:

The airline’s policy states that they have the right to remove anyone from a flight ‘whose clothing is lewd, obscene, or patently offensive’.

Personally I don't think the clothing is 'lewd', 'obscene' or 'patently offensive', but it's not up to me. The airline in essence has the right to deny boarding for any reason; if you ask on avation.se they will tell you the pilot will make the final call. I would expect that if you flew with an Iranian carrier, the standards they would apply would differ substantially from (e.g.) a Swedish carrier. I think your quest for 'definitive examples' is not going to be fruitful, as this is a judgment call. However, the link above will take you to some ridiculous decisions.

There are a wide variety of reasons why you may be denied boarding. I described some of the alleged security reasons here with references: Physical appearance and clothing, do they affect the passenger's chances of getting on the plane?

In the example in question, the reason was not security (or a pretence at security), it was (allegedly) decency. From the article:

The airline’s policy states that they have the right to remove anyone from a flight ‘whose clothing is lewd, obscene, or patently offensive’.

Personally I don't think the clothing is 'lewd', 'obscene' or 'patently offensive', but it's not up to me. The airline in essence has the right to deny boarding for any reason; if you ask on avation.se they will tell you the pilot will make the final call. I would expect that if you flew with an Iranian carrier, the standards they would apply would differ substantially from (e.g.) a Swedish carrier. I think your quest for 'definitive examples' is not going to be fruitful, as this is a judgment call. However, the link above will take you to some ridiculous decisions.

There are a wide variety of reasons why you may be denied boarding. I described some of the alleged security reasons here with references: Physical appearance and clothing, do they affect the passenger's chances of getting on the plane?

In the example in question, the reason was not security (or a pretence at security), it was (allegedly) decency. The airline in essence has the right to deny boarding for any reason; if you ask on avation.se they will tell you the pilot will make the final call. I would expect that if you flew with an Iranian carrier, the standards they would apply would differ substantially from (e.g.) a Swedish carrier. I think your quest for 'definitive examples' is not going to be fruitful, as this is a judgment call. However, the link above will take you to some ridiculous decisions.

There are a wide variety of reasons why you may be denied boarding. I described some of the alleged security reasons here with references: Physical appearance and clothing, do they affect the passenger's chances of getting on the plane?

In the example in question, the reason was not security (or a pretence at security), it was (allegedly) decency. From the article:

The airline’s policy states that they have the right to remove anyone from a flight ‘whose clothing is lewd, obscene, or patently offensive’.

Personally I don't think the clothing is 'lewd', 'obscene' or 'patently offensive', but it's not up to me. The airline in essence has the right to deny boarding for any reason; if you ask on avation.se they will tell you the pilot will make the final call. I would expect that if you flew with an Iranian carrier, the standards they would apply would differ substantially from (e.g.) a Swedish carrier. I think your quest for 'definitive examples' is not going to be fruitful, as this is a judgment call. However, the link above will take you to some ridiculous decisions.