One who writes two letters, whether with his right hand or his left; whether of one character or of two characters; whether with two inks; in any language, he is liable. R’ Yose says: They declared [writing] two letters liable only because of mark-ing, for thus would they write on the boards of the Mishkan, to know which ones were mates. Rabbi [Yehudah HaNassi] said: We find a short name which is part of a long name, SHeM from SHiMon, or SHMuel, NoaCH from NaCHor, DaN from DaNiel, GaD from GaDiel.

One who writes two letters in one period of forgetfulness is liable. [Whether] he wrote with ink, with orpiment, with vermilion, with gum, with ferrous sulphate, or with anything that marks; on two walls forming a corner, or on two pages of a ledger, that can be read together, he is liable. One who writes on his skin is liable. One who scratches on his skin, R’ Eliezer holds him liable for a sin offering. But R’ Yehoshua exempts [him].

[If] one wrote with liquids, with fruit juices, in road dust, in scribes’ dust, or with anything that does not endure, he is exempt. [If one wrote] with the back of his hand, with his foot, with his mouth, or with his elbow; [if] one wrote one letter alongside a written letter; [if] one wrote over [other] writing; [if] one intended to write a ח, but wrote two ז’s; [if one wrote] one [letter] on the ground and one [letter] on a beam; [or if] one wrote on two walls of the house, or on two pages of a ledger, that cannot be read together, he is exempt. [If] one wrote one letter as an abbreviation, R’ Yehoshua ben Beseira holds [him] liable. But the Sages exempt [him].

One who writes two letters in two periods of forgetfulness, one in the morning and one in the afternoon, Rabban Gamliel holds [him] liable. But the Sages exempt [him].