The 206th prohibition is that a Nazirite is forbidden from eating grape skins.

The source of this commandment is G‑d's statement,1 "He may not eat [anything coming from the grape, from its pits to] its skin."

If he eats a kezayis of them, his punishment is lashes.

The proof that these five prohibitions — wine, grapes, raisins, pits, and skins — count as separate mitzvos is because there is a separate punishment of lashes for each one individually. In the words of the Mishneh:2 "There are separate punishments for the wine, the grapes, the skins and the pits." Tractate Nazir3 explains that one who ate [a kezayis each of] grapes, raisins, skins and pits, and squeezed a cluster of grapes and drank [a revi'is of the juice] receives five sets of lashes.

[Therefore, although the Mishneh just mentions grapes, raisins are counted as a separate prohibition.

From this same Gemara we can prove that wine vinegar is not counted separately, but is included under the prohibition of wine:]

The Gemara then tries to prove that the Mishneh omitted a case of lashes in addition to these five — [an inclusive prohibition just] because he is a Nazirite.4 The Gemara responds, "It also omitted mention of the prohibition5 of not breaking one's word," rather than giving a [more obvious] response, "It omitted the prohibition of vinegar."

The reason it could not [give that response] is because there are not separate lashes given for the prohibition on wine and on vinegar. This is because the whole prohibition of vinegar is because it is primarily wine, as we explained above.6 It is as if the verse says that the prohibition [on wine] does not disappear when it becomes spoiled [i.e., turns to vinegar].

One must keep in mind that these [five grape] products which are prohibited to a Nazirite can all be combined to make up one kezayis, and one receives lashes for eating one kezayis made up of all of them.