Hi folks,
here in continental Europe we seem to have a similar system in most countries, I give you the example how it works in Germany, but it's the same in Swtzerland, Austria, Denmark, Sweden, Netherlans etc.): 99,9% of all golf clubs are member in the national golf federation. Every member of a golf club gets a credit card sized identification card which is issued yearly stating name, handicap and home club. Also the card shows the logo of the National Golf Federation and the European Golf Federation (some times on the back of the card)
I show this card whenever I arrive at the check-in desk of a golf club I am visiting. My home club will admit anyone on a greenfee basis showing the before mentionned card and on the same basis I'll be admitted at any other golf club in Germany against paying a greenfee, be it a very private or even a public golf course. Some clubs especially in metropolitain areas do have restriction as they do not allow geust players not playing with a member on weekend.
This system avoids writing letters of introduction and has been used at least 20 years now.....Personal information contained in the magnetic stripe on the card allows clubs where I am visiting to wipe the card through a reader and printing out greenfee tickets or tournament score cards without having to type my name or details into the computer.
Also there is a national federation of golf players without a home club (a similar club also exists in other continental countries like Switzerland or the Netherlands) - this official national federation is for people who, for whatever reason (financial reason or because they are constantly moving in between different towns or because they just don't like joining a club), are choosing not to join a private club. They will also receive a credit-card sized yearly plastic card similar to the before mentionned one, the only disadvantage is that some very private clubs do not admit these players or only admit them against a severe extra charge...
Christoph