All of them had different rules, and the experience was interesting. And for all of them the Exchange Organisers worked extremely hard and did an excellent job.
Three of the four exchanges were anonymous, i.e. the Exchange Organiser posted the fiction for everyone, and the stories remained anonymous until the appropriate reveal. One of the exchanges wasn't anonymous; writers posted their own stories.
For three of the exchanges you were sent the name of the person for whom you were writing, as well as a copy of their sign-up details. For the other one, you were allocated a number along with the sign-up details, and it was suggested that it might be more fun to write without knowing the name of the person for whom you were writing. Given that all sign-up details remained on the Community for all to see, I don't know whether people did this or not, or whether they preferred to know the name of the person.
One Exchange Organiser posted one story each day beginning on 1st December. One posted several stories a day beginning mid-December. One posted them all on Christmas Eve. The stories we posted ourselves were all posted on New Year's Day.
TYPE OF STORY
The 'rules' regrading these were even more diverse.
One Fiction Exchange could be said to be more geared towards the writer rather than the recipient. When signing up you were asked, as the writer, to state the type of story you would write (i.e. slash, gen or het); to list the pairings you would be willing to write; any other characters you would be willing to write, and three things that you wouldn't write.
As the recipient you were asked to state what type of story you wanted (again slash, gen or het); what pairing (if slash or het), and what central character if gen you wanted, and three things you didn't want included. You also had the opportunity to give the writer an idea of what you might like in your story, e.g. theme, plot, etc. but the writer didn't have to pay any attention to this. They were only bound by the type of story, pairing and 'not wants'.
One Fiction Exchange could be said to be geared slightly more towards the recipient rather than the writer. As recipient, when signing up, you were asked to state the type of story (slash, gen or either) you wanted; three prompts, e.g. a word, a place, a character, and the writer was asked to try to include at least one of these in the story (but it was noted that it may not happen, the prompts were guidelines only); the kind of thing the story should be about, humour, romance, etc.; also (as this particular exchange also offered a chance for artists to take part) what kind of art you would like to receive, icons, wallpaper, etc.
As a writer the only thing you were asked to state was whether you would write slash, gen or either. There was no specific place for the writer to state anything that a writer felt they couldn't write. This lack of asking writers to state anything they couldn't write, could lead to the writer receiving an assignment containing three prompts, and a couple of themes they simply could not fulfil. However, as mentioned above, this exchange did state that it might not be possible for the writer to fulfil the recipients 'prompts', so there was lea-way here. And writers were aware that they might be given something they would prefer not to write, as when signing up it was made clear that the assignments were randomly matched by slash/gen/either preferences only.
One Fiction Exchange was slash only, and stated that there were to be no AU stories. As far as the writer-recipient bias went, it was well balanced (unless you happened to be a fan of AU stories). As the recipient you were asked to state three to five themes (hurt/comfort, established relationship, etc); any kinks you'd like to see in the story (BDSM, voyeurism, etc), if you happen to be the kind of person who didn't enjoy/want kinks, it was also perfectly fine to say that you wanted the story to be kink free; any squicks you didn't want to be included (death, BDSM, etc); and whether you were happy for pairings other than the main one to be included.
As the writer you could state any themes you refused to write (partner betrayal, partner beating, etc.); and any kinks that you refused to write. If you simply couldn't/wouldn't write any kinks at all, it might have been difficult, assuming everyone listed at least one kink, to allocate you as a writer. However, the term 'kinks' clearly meant different things to different people, and covered a huge range of things - some of which I personally wouldn't have called a kink. Which just goes to show that very little in fandom is black and white and has only one interpretation.
The final one was also extremely well balanced, probably even slightly better than the one above as it didn't disallow anything, nor did it use terms such as 'kink', between writer-recipient. As the recipient you basically got to list the characters and/or pairing you wanted; any theme; genre (slash, gen or het); rating; scenario; you also got to state what you didn't want as far as pairings, characters, scenario, etc. went - simply put, you could almost custom-build your own story.
As the writer you could state which pairings and/or characters you both could and couldn't write; also the scenarios; genres; rating; etc. (exactly the same as recipient); you also got to state all of the things that you couldn't write.
The main downside with this exchange was that given the potential number of pairings (both slash and het) involved, the possibility that a writer and recipient could not be matched, was unfortunately a very real one.
Given that all four exchanges I was involved in had different rules, etc. I would venture to guess that there are quite a few more variations amongst the other exchanges.
There were also other differences (based on these four exchanges and comments I've heard from other people). For example, some Exchange Organisers didn't mind the writers using beta readers who were taking part in the exchange; others didn't want that to happen. Some Exchange Organisers didn't want people speculating about who wrote what (and naturally this happened both deliberately and non-deliberately); others actively encouraged people to guess. Some Exchange Organisers allowed anonymous 'thanking' for comments left, other asked that there be no responses until the reveal. The length of time between the stories being posted and the reveal taking place also varied.
I thoroughly enjoyed, in all cases, writing to a deadline, and also to tailoring my fiction, as far as possible, to the desires of the recipient. This was difficult in the case of the Fiction Exchange whereby the recipient didn't have to give the writer any idea of what they wanted included, as all I had to go on was what the person didn't want. Ironically enough this probably, on this occasion, turned out to be a good thing, as the story I wrote ended up being reassigned to a different recipient (a friend, it so happens). Thus, maybe had I been given some 'wants', the reassignment might not have been possible, and the Exchange Organiser would have had to have called in a pinch hitter. However, I certainly found this story the most difficult to write.
In the other three cases I ended up writing for three people whom I 'knew', albeit with varying degrees of knowledge. Thus, I was able to tailor (as far as possible) the stories to their wants, using the sign-up details and what personal knowledge I had of them. In one case I also enlisted the aid of a mutual friend, who wasn't taking part in the Exchange, who knew one of the people better than I did, and who was able to do a little detective work for me.
What I didn't enjoy was the whole anonymous thing. It just didn't work for me, for various reasons. Even though I knew that the people who kindly left comments on my stories weren't expecting any kind of acknowledgement until the reveal was done, it bothered me (more than I'd been expecting) that I couldn't acknowledge them at the time. In fact it's fair to say that it made me quite miserable, because I worried about it. Illogical, I know, but there you are. Nor could I thank my beta reader at the time of posting the story, nor any other help I'd had, and again that I found made me uncomfortable.
I also found that I worried a great deal, from the moment I'd sent my story to the Exchange Organiser, until the recipient had commented on the story, about whether she would like it, etc. etc. This was actually something I had no need to worry about, as all four recipients were very pleased with their stories, and when I saw that they were happy, that made me happy.
I also wanted to say thank you personally to the person who had written my story, not just do a 'Dear Secret Santa' letter. Somehow doing it days or weeks or a month later, isn't the same as being able to do it at the time. Again, maybe illogical, but that's how I felt about it.
So all in all, despite the enjoyment I got from writing the stories, and from tailoring them to my recipients' tastes, the whole Anonymous Fiction Exchange thing was sadly, for me, more negative than positive. Thus, I seriously doubt whether I will take part in another anonymous one, (indeed, I'm not even certain I'd take part in another exchange at all), unless I'm the one organising it. I can get my 'deadline fix' from writing for zines or challenges, and if I want to write tailored fiction, I can always do so without the need for a challenge. So for future anonymous ones, I will be a reader not a writer.
All experiences are learning ones, I feel. Thus despite the whole thing being more negative than positive for me, I am glad that I did participate in the exchanges.