Playing the devil's advocate for a moment... What I perceive as a memory trigger may not be what you consider a memory trigger?  
   Perhaps if TER had some sort of system, in which providers could simply record that they've: Screened someone, Seen someone and would see them again. It could be updated if you saw them again, or removed if you've discovered bad behavior on their part. You could even give it a catchy name like "Good list" or "Whitelist"... or something like that.
   Although, I don't know if this idea would ever catch on.

thats why

I shave the head and have the Mickey Mouse tatt. noone forgets that LOL

This is why I like p411's system of OKs - you can just select the person's ID and mark them as 'ok', and you can always go back and look to see if you've seen them. I also wish TER had a system like that to help providers stay organized.

It may be worth finding your own system that does not rely on memory triggers. Obviously, do not save emails or phone numbers/any sort of personal information, but sometimes just storing a key word associated with the email can help. I do agree that without proper information, it can be hard to give a reference if you haven't seen someone in years. Personally, I wouldn't accept only one reference from someone years ago anyway, but that is her prerogative of course.  

What also might help is if gentlemen made us aware that they would like to use us as a reference in the future-- either during the visit or via email after the visit sometime. If I know someone needs to use me as one, and it is time sensitive, I am much more likely to pay extra attention to my email for him. This however doesn't solve the problem of requesting references years later...  

I sympathize with your plight and think there is lots of good information here for the guys. Thanks for posting!

Some guys don't participate in the hobby that often

Of those they do see, many may no longer be active for long, limiting their choices for references.  

I suspect many neglect to ask if the provider will serve as a reference

Some providers don't like to provide references.  For various reasons.  

Some who hobby outside of major metro areas face other issues they have to think about.  

Just a few real world reasons why a hobbyist might not have much recent to offer in the way of people to check with.

If it bothers you, some providers clearly state on their website how long they are willing to serve as a possible reference--if you don't do that already, might be something to consider.  I've seen limits of a year or two (erased with a repeat visit of course) a number of times.

I had a reference request this week. The information the gentleman provided was:

"Jim"

and nothing else!!! After exchanging six emails, I was finally able to determine who it was. He had also changed his hobby name, email address and hobby phone number since he had seen me. Very time consuming for all, including the client.

Jillian