If the Beis Din instructs the Ganav that he is Chayav to pay for the Geneivah if he subsequently slaughters or sells the stolen animal he is Chayav four or five. (1)
R. Yochanan says that a Ganav cannot be Makdish a stolen object before Yi'ush because it does not belong to him and the owner also cannot be Makdish it because it is not in his Reshus.
Kerem Reva'i is marked with clumps of dirt in order to signify that just like a person benefits from dirt so too one may benefit from Keren Reva'i after it has been redeemed.
Orlah is marked with shards of pottery in order to signify just as one does not benefit from shards of pottery so too one may not benefit from Orlah.
Cemeteries are marked with lime since lime is white like bones.
R. Shimon Ben Gamliel says that only Orlah and Reva'i of Shevi'is is marked because it is Hefker. (2)
The Tzenu'im redeemed all of the Reva'i that was collected from their fields so that whoever picks the produce will not transgress the prohibition of eating Reva'i outside of Yerushalayim.
R. Yochanan says that every time R. Shimon Ben Gamliel is mentioned in the Mishnah the Halachah is like him with three exceptions.
Rebbi Yehudah says that every morning the owner of a field should say that everything the poor will collect from this field shall be Hefker. (3)
R. Dosa says that every evening the owner shall say that everything the poor collected from the field shall be Hefker.
Someone who buys wine from a Kusi may say that the Lugin that I will separate for Terumah and Ma'aser later on shall be Terumah and Ma'aser and he should redeem the Ma'aser Sheni immediately and he may drink the wine according to R. Meir. (4)
R. Yochanan says that brothers who split an inheritance are considered buyers not inheritors and must return their fields to each other at Yovel. (5)
Someone who steals from a Ganav does not pay Kefel.
R. Meir holds that Ma'aser Sheni is Mamon Gavohah but Torah puts it in his Reshus for redemption and therefore an owner who redeems his own Ma'aser Sheni must pay an additional fifth.
According to R. Meir Reva'i is learned out with a Gezeirah Shaveh from Ma'aser Sheni that it is Mamon Gavohah.
A BIT MORE
1. When Beis Din instructs the Ganav that he is Chayav to pay it is not considered a Gmar Din and therefore he is still considered a Ganav not a Gazlan and he is obligated to pay four or five.
2. However, the Orlah and Reva'i of other years is not Hefker and we do not make a Takanah for a Ganav and we are not concerned that he may transgress the prohibition of Orlah and Shevi'is.
3. The concern is that when the poor collect the Leket they will mistakenly also collect produce that is not Leket and is Chayav in Ma'aser therefore the owner is Mafkir it so that it will be Patur from Ma'aser.
4. R. Meir holds Yesh Bereirah and therefore if someone bought wine Erev Shabbos at twilight and does not have time to separate the Terumah before Shabbos he may say that the Lugin that he will separate after Shabbos shall be Terumah and Ma'aser and he may drink the wine on Shabbos and separate the Terumah and Ma'aser after Shabbos. Since he holds Yesh Bereirah we assume that the Terumah and Ma'aser that he separated after Shabbos is the same Terumah and Ma'aser that was Chal on Erev Shabbos at twilight.
5. R. Yochanan holds Ein Bereirah and we don't assume that the share that each brother received was the share that was theirs from the time the father died and therefore we look at it as of the brother traded their shares with each other and they are considered buyers and they must return their shares to each other at Yovel.
YIUSH OF GENEIVAH
R. Dosa says that every evening the owner shall say that everything the poor collected from the field shall be Hefker. Why does the owner have to be Mafkir it? Why isn't it Patur from Ma'aser because of the Yi'ush of the owner? The Gemara states in Bava Metzi'ah that Yi'ush is Patur from Ma'aser! Tosfos explains that Yi'ush is only Patur from Ma'aser for an Aveidah because the Yi'ush allows the finder to keep the Aveidah. However, with respect to a stolen object even according to the opinion that Yi'ush is Koneh the person who is Koneh is obligated to pay the value of the stolen object and therefore it is not the same as Hefker and it is not Patur from Ma'aser.
Someone who has Neta Reva'i during the year of Shemitah since anyone may pick the produce he must mark it with clumps of dirt so that people will be aware that it is Reva'i and will not eat it without redeeming it first. If he has Orlah he must mark it with shards of pottery so that people will not pick it because if it is marked with clumps of dirt maybe it will scatter as Orlah is very stringent because it is forbidden b'Hana'ah. The Tzenu'im put down money during the year of Shemitah and they said that anything that is picked from the Reva'i shall be redeemed on this money because it is forbidden to redeem it while it is attached to the ground. (Rambam Hilchos Ma'aser Sheni 9:7)