Used stamps exchanges.

Basic rules of the project are known - 100 used unique stamps in good condition.
( http://100stamps.club/discussions/messages/141 )
But this project have several additional rules. I have collected them here:

1. In progress allowances ( http://100stamps.club/discussions/messages/88 )
sent 0 - limit (of traveling letters) 2
sent 1 - limit 3
sent 3 - limit 4
sent 5 - limit 5
sent 10 - limit 6
sent 20 - limit 7
sent 30 - limit 8 (it's maximum)

2. Stamps to members not active any more.
"You don't receive tickets of members that have not logged in for more than... 2 weeks (14 days)."
( http://100stamps.club/discussions/messages/138 )

3. If your envelope gets lost (90 days and more). "After 90 days the letters are marked as expired and don't count as traveling letters." ( http://100stamps.club/discussions/messages/170 )
"A slot is lost if the lot does not reach its destination and is not registered. The exchange will expire but the slot will not be reassigned... A slot is lost if the lot does not reach its destination and is not registered. The exchange will expire but the slot will not be reassigned. So if someone requests an address and its not actually sending the lot, the receiver its losing that slot."
( http://100stamps.club/discussions/messages/66 )

4. If you receive a negative rating (1 or 2).
( http://100stamps.club/discussions/messages/140 or http://100stamps.club/discussions/messages/128)
"If a member has 1 negative rating in the last 10 exchanges, a warning message will be displayed in the "Send stamps" page but there wont be a limitation on the maximum travelling letters (2 letters).
For 2 negative ratings, sending new letters will be suspended.
The ratings can be changed if you contact your partner and find a solution to improve your previous exchange. Maybe a partial resend."

5. Ranking
( http://100stamps.club/discussions/messages/107 )
In the ranking are listed only the members that have been active in the last year. So, after a year of inactivity they wont appear in the ranking until they log in again.

You can also add anything else (to be continued... :)

Continue...
9. If you temporarily don't want to receive the stamps (the long trip, vacations, temporal problems with your post office service, etc.) "If you delete your address you automatically suspend yourself both from sending and from receiving stamps." ( http://100stamps.club/discussions/messages/168 ).

Hola, Francesc!
Vamos a sobrevivir eso :)
Let it remain on the conscience of the senders.

Hola Natalia :)
What to do with envelopes somebody never sent?

Continue...

6. Skip option revised
"One skip in 30 days...
A skip will last one year. You will receive that profile again in the future."
( http://100stamps.club/discussions/messages/195 )

7. Change country
I don't know somebody changed his own country. I think... for example... a member doesn't want to have a swap from Germany and he selects Germany as a country and makes the option "From all countries, excluding my own country". May be otherwise...
( http://100stamps.club/discussions/messages/111 )

8. Additional slots
"Everybody receives an extra slot proportionally with the number of positive sent exchanges."
( http://100stamps.club/discussions/messages/74 )
"Additional slots are given to members to compensate for the expired lots and to allow new members to enter the system.
These extra lots are given proportionally to everybody. For 'x' positive exchanges (4 or 5 stars) you receive an extra slot. The 'x' number varies depending on how many new slots are needed. It depends on how many new members join and how many exchanges expire.
Starting with this month [July 2016] only the positive exchanges are considered for extra slots."
( http://100stamps.club/discussions/messages/66 )

I think it's a very complex moral thing.
I think this was originally made in order to always have an address for those who wish to make a swap.
(http://www100stamps.club/discussions/messages/14)
Just an example - http://100stamps.club/profile/Williamvg
2015.12.02 (3*) -> 2015.12.10
2015.12.24 (4*) -> 2016.01.01
2016.01.27 (3*) -> 2016.01.31
2016.02.02 (4*) -> 2016.02.04
2016.02.22 (5*) -> 2016.02.24
2016.02.23 (5*) -> 2016.02.24
additional lot -> 2016.02.24
2016.03.16 (4*) -> 2016.03.19
An additional lot was sent after 4 positive and 2 neutral feedbacks.
And now, as we see, William was left the project (missing for more than a year), having received more letters (8) than sent (7). Whether it is good or bad depends on the moral attributes of the person.
For example, guyana1230 did not want to follow in a such manner (http://100stamps.club/discussions/messages/168). I applaud her for this noble step.
I wanted to know for how many positive rates an additional lot is given now. What is the number 'x' Danubius wrote about? Here are my swaps (I have only positive feedbacks just now):
RU-487 Ca (21.11.2017-16.12.2017) - CA-815 (16.12.2017-08.01.2018)
RU-490 Es (23.11.2017-18.12.2017) - CA-819 (18.12.2017-08.01.2018)
RU-508 De (18.12.2017-08.01.2018) - DE-??? (08.01.2018-...)
RU-535 Au (14.01.2018-25.01.2018) - FR-629 (25.01.2018-20.02.2018)
RU-526 Es (09.01.2018-01.02.2018) - CZ-245 (02.02.2018-20.02.2018)
RU-548 Ca (28.01.2018-22.02.2018) - FI-817 (22.02.2018-10.03.2018)
RU-568 Nl (20.02.2018-08.03.2018) - HR-330 (08.03.2018-27.03.2018)
RU-578 Fr (01.03.2018-16.03.2018) - NL-1867 (16.03.2018-02.04.2018)
Additional lot - CN-??? (17.03.2018-...)
RU-597 Ru (18.03.2018-02.04.2018) - SI-415 (02.04.2018-20.04.2018)
RU-595 Cz (18.03.2018-04.04.2018) - FR-771 (04.04.2018-16.04.2018)
RU-596 Us (18.03.2018-16.04.2018) - US-1185 (16.04.2018-03.05.2018)
RU-610 Nl (02.04.2018-20.04.2018) - ES-1182 (24.04.2018-08.05.2018)
RU-609 No (02.04.2018-23.04.2018) - DE-964 (25.04.2018-07.05.2018)
RU-622 Be (13.04.2018-30.04.2018) - CA-1035 (30.04.2018-18.05.2018)
RU-623 Es (13.04.2018-05.05.2018) - FI-893 (05.05.2018-18.05.2018)
RU-621 Ca (13.04.2018-10.05.2018) - FI-900 (11.05.2018-06.06.2018)
Additional lot - ES-1212 (11.05.2018-06.06.2018)
RU-635 No (02.05.2018-15.05.2018) - UA-133 (17.05.2018-14.06.2018)
RU-637 Fi (02.05.2018-16.05.2018) - CA-1074 (18.05.2018-06.06.2018)
RU-636 Nl (02.05.2018-17.05.2018) - IT-457 (18.05.2018-14.06.2018)
RU-656 Nl (13.05.2018-23.05.2018) - NO-490 (23.05.2018-06.06.2018)
RU-662 Fi (16.05.2018-03.06.2018) - AU-191 (04.06.2018-20.06.2018)
RU-655 My (09.05.2018-09.06.2018) - HR-419 (09.06.2018-16.07.2018)
RU-661 Nl (16.05.2018-10.06.2018) - NL-2112 (10.06.2018-26.06.2018)
RU-638 Nz (02.05.2018-13.06.2018) - NL-2123 (14.06.2018-09.07.2018)
Additional lot - US-1326 (16.06.2018-04.07.2018)
RU-687 Hr (10.06.2018-19.06.2018) - DK-471 (19.06.2018-02.07.2018)
RU-685 Si (10.06.2018-22.06.2018) - IL-94 (22.06.2018-16.07.2018)
RU-683 Ua (10.06.2018-03.07.2018) -
RU-697 Nl (19.06.2018-06.07.2018) -
RU-701 Hr (24.06.2018-12.07.2018) -
RU-698 It (19.06.2018-13.07.2018) -
RU-702 My (24.06.2018-16.07.2018) -

It turns out now that an additional lot is given after 8 positive feedbacks. Since there is no significant increase in the club members, I think that Danubius would have to increase this slot several times to prevent the system degeneration ... (if someone gets more, then there will be those who do not receive letters in return).

Those above are the current settings. I intended to put them on a separate page for some time. I hope to do it soon.

Natalia,
Thank you for the clarification.

Simplemente, brillante :)
muy buen resumen !! :)

dgdecker, all these rules are from the answer messages of Danubius (Admin of the project), the references I gave below each ones.
About 2 weeks - you only can't receive the someone address if he is absent more than 2 weeks. But this function appears again just after his reauthorization.

A few questions for clarification...

Are these current rules of the Club? Or proposals for possible changes?
If they are current rules, where are they found on the website?

If proposals... item 2 is of concern. The 2week period might be two short. What is someone takes a holiday or becomes ill and cannot access account. I have been away and this is my first internet access in two and a half weeks.

Thanks Natalia - very good summary.