(a) According to the Tana Kama, a 'Kuf' on a found vessel denotes 'Korban' - meaning that it or its contents (see previous Mishnah) are Hekdesh.
(b) 'Mem', 'Daled', 'Tes' and 'Taf' stand for - 'Ma'aser Sheni' (see Tiferes Yisrael) 'Demai', 'Tevel' respectively and 'Terumah'.
(c) The owner would have done that - in the time when the evil regime forbade Jews to fulfill Mitzvos.
(d) Rebbi Yossi disagrees. He maintains that ...
1. ... in this case - the letters symbolize names (Kehas, Daniel, Tuvya or Tanchum).
2. ... in a case where one found a barrel with the word 'Terumah' written on it - the contents are nevertheless Chulin, because we assume that it was once used for Terumah, but no longer (see Tiferes Yisrael).
(a) The Mishnah rules that if someone tells his son that he will find Ma'aser Sheni in a certain corner, and he finds it in another corner - what he finds is Chulin (see Tiferes Yisrael).
(b) And if he told him that he would find ...
1. ... a Manah, but he found two - then one Manah is Ma'aser, and the one, Chulin (see Perek 2, Mishnah 6).
2. ... two Manah, but he found only one - then it is Ma'aser.