The boarding pass typically lists two times: the time of departure and the time of boarding. For many airline passengers, the only significant one is time of departure.

That’s because “time of boarding” marks only the beginning of a long process of which they are at the end. The parade of passengers qualifying for priority boarding has become so long that on some flights, half the passengers have this status. That makes for a neat split between — and here is the bottom line — those who have overhead bin space and those who have not.

As most airlines started charging for checked baggage, the incentives for carting it all on have multiplied. Boarders in the lower castes well know the inconvenience of taking seats under bins already stuffed with a priority boarder’s life possessions.

Anyhow, here’s a mixed sampling of the boarding classes:

First class.

Oneworld Ruby, Sapphire and Emerald.

SkyTeam Elite, SkyTeam Elite Plus.

Star Alliance Silver, Star Alliance Gold.

Dividend Miles Silver Preferred, Gold Preferred, Platinum Preferred, Chairman’s Preferred.

AAdvantage Gold, AAdvantage Platinum, AAdvantage Executive Platinum.

US Airways Premier World MasterCard.

US Airways Visa Signature card.

Other passengers enjoying priority treatment are those needing “extra assistance” and families traveling with young children.

“Persons with help animals may now board.”

Followed by help animals traveling alone.

One much-reviled group is what airline employees call “miracle” passengers. These are able-bodied people who demand wheelchairs — thus getting themselves wheeled to the front of lines — and then skip off when the flight is over.

Airlines employ a multitude of boarding styles: outside-in, rear-to-front, reverse pyramid, rotating zone, zone/block and random. Passengers familiar with these systems can use that knowledge to their advantage. Perfectly legal.

Less sophisticated are those whom seasoned fliers call “gate lice.” These are passengers who clog up the gateway even though their group has not been invited to board. They can be identified by their steamer-trunks-on-wheels and nervous look. For them, just a few positions up the queue could mean the difference between getting desperately needed bin space and facing new hassles.

As airlines multiply the categories of special status, many “elite” passengers are feeling less elite. The bottom rungs — the Aquamarine Preferred — are competing against others with conferred status through not the miles they fly but the dollars spent on the airline credit card. And some get bumped up the boarding hierarchy by paying a simple fee.

These days, the lower elites are also having a harder time obtaining an upgrade to a finer seat. Some travel writers advise that if you want an upgrade, your chances improve if you buy an expensive ticket on a less popular route and avoid peak times. And don’t go nonstop.

Of course, there’s always the bus.

For the airlines, time at the gate costs them. So getting people on quickly is a goal.

Some airlines now let those vowing not to use an overhead bin to board first because they don’t block the aisles with big bags. This works on an honor system, and humans can be frail, especially in trying situations.

A few airlines — Spirit and Frontier, for example — now charge fees for carry-on bags. And Southwest Airlines still lets passengers check in one or two bags at no extra cost. Good for all of them. They’re blurring the advantages of lugging luggage onto the plane.

As we see, the boarding process can injure a sensitive soul’s feelings of self-esteem. But it can also help cure a fear of flying. The stress of getting into a seat is such that once people do, they may not care much what happens next.

Now relax, and enjoy your flight.

Froma Harrop is a syndicated columnist. Follow her on Twitter @FromaHarrop. She can also be reached by email at: fharrop@gmail.com.