Translation:Shulchan Aruch/Orach Chaim/299
1. To Neither Eat, Drink, Nor Perform Any Work Before Reciting Havdalah, 10 Seifim: It is forbidden to eat anything, or even to drink wine or other drinks besides water, from the time it gets dark until one makes Havdalah. However, if one was sitting and eating while it is still day and he forgot, he does not have to stop [even from drinking. Beis Yosef]. If one was sitting and drinking and he forgot, he must stop. And there are those who say, that this is the rule if one is in doubt if one forgot; but if one certainly forgot - even if one was sitting and eating a slice by mouth and then says Havdalah he may finish his meal. RAMA: The simple custom is like the first opinion.
2. If one was drinking, and said 'let us go and make havdalah', then changed his mind and drank before havdalah, one need not go back and bless again. And there is one who disagrees on this.
3. When a person makes an interruption when drinking in order to recite Havdalah, he does not have to say Boreh Pri HaGafen over the havdalah cup. And there are those who say he must.
4. When a person was eating and forgot that we said that he does not have to stop, he finishes his meal and says Birkat HaMazon over the cup and afterwards says havdalah over it. If he has two cups, he says Birkat HaMazon over one and havdalah over the other.
5. If one erred and ate something before making havdalah he can say havdalah afterwards.
6. If one forgot and did not make havdalah on Saturday night can make havdalah until the end of Tuesday. There are those who say that we do not make havdalah except for all day Sunday and no further. And specifically Boreh Pri HaGafen, and מבדיל בין קודש לחול. However, over a candle and spices we do not make a blessing except on Saturday night. There is one who says that this reason, which we fulfill, applies only to havdalah at night on Saturday night. However if one does not make havdalah at night because of this reason, it is not havdalah. RAMA: The essence is like the first opinion. And one who fasts three days and three nights hears havdalah from others. And if there are no others near him, he can make havdalah in Shabbat during the day, then drink and then afterwards accept the fast upon him. See Siman 553.
7. One who makes havdalah over wine at his table, even if he made havdalah prior to washing his hands, the wine involved in the meal is exempt and need not have a blessing recited over it. And there are those who say that it is not exempt unless he washed his hands prior to making havdalah. RAMA: And if one made havdalah first one must afterwards say ברכת מעין שלש. (the afterblessing al Hagefen, etc). [Tosefos; Mordechai]
8. When wine used for a meal is exempted and a blessing is not required to be made over it, it is also not required to say the after blessing over the havdalah cup. And if he has only one cup and he thinks that more wine should be brought to him and he says havdalah over it, and then after wards they do not in fact bring him more wine, and then he says Birkat HaMazon without a cup, there is one who says that one must make the after blessing over the havdalah cup.
9. One who desires to partake of a meal immediately after Havdalah should be careful not to bring bread to the table before he recites Havdalah. If it was brought, he must cover it because it is early in the verse, and he must proceed as if it was not brought.
10. It is forbidden to do any work before havdalah. And if he said havdalah in the prayer it is permitted even though he has not yet made havdalah over the cup. And if one needs to do work prior to saying havdalah in the prayer, he says 'Hamavdil' without a blessing (i.e. without G-d's Name) and then he may do work. RAMA: And likewise women who do not recite the Evening Service and [thus] do not recite Havdalah in the Evening Service on Saturday night, should be instructed to recite Baruch HaMavdil bein kodesh lechol before they perform a labor [forbidden on Shabbos when they have not yet heard] Havdalah recited over a cup [of wine]. [Kol Bo]. There are those who say that all this is regarding a labor that would be forbidden on Shabbat, such as writing or weaving. But lighting a lamp or going from domain to domain does not qualify for this rule. And from this there is a widespread custom to be lenient to light lamps immediately after the congregation says 'Barchu', but the essence is like the first opinion. And there are those who say to draw water from wells or natural springs every Saturday night, because the well of Miriam passes through all the wells and natural springs every Saturday night. And one who touches it and drinks from it will be healed from all his afflictions [Kol Bo]. And I did not see (anything) about this custom. And see above Siman 263, that he who adds from the profane to the holy whether it is permitted to say to him after he has made havdalah to do work for him.