Blue Post
The blue post is a course marking whose meaning each facility defines by local rule — in the rulebook the colour blue is not uniformly defined.
The rulebook of the R&A and USGA knows mainly white for out, yellow and red for penalty areas. Blue posts do not belong to these standardised colours. Many courses still use blue for their own markings: often for ground under repair without a drawn line, sometimes for the edge of protected zones or for drop points. The only binding source is the local rule of your facility, which stands on the scorecard or on the notice board. Anyone who cannot place the colour asks at the club office or among fellow players before the round.
In practice that means: never rely on assumptions about post colours. An example: your ball lies next to a row of blue posts, your stance is affected by a cordoned-off area. If the local rule says blue marks ground under repair, you get a free drop without penalty. If blue instead marks only a path routing for carts, you play the ball as it lies. The difference between the two cases costs you penalty strokes or unnecessarily bad lies in doubt.
A typical mistake is dropping spontaneously because "blue posts surely mean relief". First clarify the local rule, then act. Rule of thumb: the standard colours white, yellow and red are the same everywhere, all other colours are a matter for the facility. If you play unfamiliar courses more often, cast a glance at the local rules before teeing off — that saves discussions during the round and errors on the scorecard.
FAQ
Does a blue post always mean relief without penalty?
No, the colour blue is not defined in the official rulebook. Whether ground under repair, a protected zone or only a cart path routing lies behind blue posts is decided solely by the local rule of the facility. Never rely on an assumption — in doubt it costs you penalty strokes.
Where do I find out what the post colours on my course mean?
The binding source is the local rule, usually found on the scorecard or on the notice board in the clubhouse. On unfamiliar courses a quick look before teeing off or a question at the club office is worth it. It takes two minutes and saves discussions during the round.
What do I do if I do not know the meaning of a post during the round?
The safest option is to play the ball as it lies or clarify the situation with your fellow players. Do not simply drop because you suspect the colour means relief. Only the standard colours white, yellow and red apply the same everywhere — everything else is a matter for the facility in question.