Siman 670
Presented here for study, not as a practical ruling. The Shulchan Aruch rules by Sephardi custom, the Rema's glosses by Ashkenazi custom, and the Kitzur follows Ashkenazi custom. For a practical question, ask your rabbi.
א בְּכ"ה בְּכִסְלֵו מַתְחִילִין שְׁמוֹנַת יְמֵי חֲנֻכָּה וַאֲסוּרִים בְּהֶסְפֵּד וְתַעֲנִית, אֲבָל מֻתָּרִין בַּעֲשִׂיַּת מְלָאכָה; וְנוֹהֲגוֹת הַנָּשִׁים שֶׁלֹּא לַעֲשׂוֹת מְלָאכָה בְּעוֹד שֶׁהַנֵּרוֹת דּוֹלְקוֹת, וְיֵשׁ מִי שֶׁאוֹמֵר שֶׁאֵין לְהָקֵל לָהֶם.
1 On the 25th of Kislev (start) the eight days of Hanukkah, and they are prohibited for eulogizing and fasting, but are permitted for doing work. The women have made it a custom not to do work while the candles are burning. And there is [an opinion] that says that we may not be lenient for them.
ב רִבּוּי הַסְעֻדּוֹת שֶׁמַּרְבִּים בָּהֶם הֵם סְעֻדּוֹת הָרְשׁוּת, שֶׁלֹּא קְבָעוּם לְמִשְׁתֶּה וְשִׂמְחָה. הַגָּה: וְיֵשׁ אוֹמְרִים שֶׁיֵּשׁ קְצָת מִצְוָה בְּרִבּוּי הַסְּעֻדּוֹת, מִשּׁוּם דִּבְאוֹתָן הַיָּמִים הָיָה חֲנֻכַּת הַמִּזְבֵּחַ (מהר"א מִפְּרַאג). וְנוֹהֲגִין לוֹמַר זְמִירוֹת וּשְׁבָחוֹת בַּסְּעֻדּוֹת שֶׁמַּרְבִּים בָּהֶם, וְאָז הָוֵי סְעֻדַּת מִצְוָה (מִנְהָגִים). יֵשׁ אוֹמְרִים שֶׁיֵּשׁ לֶאֱכֹל גְּבִינָה בַּחֲנֻכָּה לְפִי שֶׁהַנֵּס נַעֲשָׂה בֶּחָלָב שֶׁהֶאֱכִילָה יְהוּדִית אֶת הָאוֹיֵב (כָּל בּוֹ וְרַ"ן).
2 The many meals which we add on [these days] are voluntary meals, since [the Sages] did not establish them as [days of] feasting and joy. Rema: But some say that there is somewhat of a mitzvah in adding meals, because during those days was the Dedication of the Altar (Abraham Kara of Prague). It is the custom to recite hymns and songs of praise during the feasts added on them, and then they are mitzvah meals (Book of Customs). Some say that cheese should be eaten during Hanukkah, because a miracle was done though milk which Yehudit fed the enemy. (Kol Bo and Nissim of Gerona).
ג אֵין מַסְפִּידִין בָּהֶם אֶלָּא לְחָכָם בְּפָנָיו. הַגָּה: וְאֵין מִתְעַנִּין יוֹם שֶׁמֵּת בּוֹ אָב אוֹ אֵם; וְתַעֲנִית חֲלוֹם בַּחֲנֻכָּה, עַיֵּן לְעֵיל סִימָן תקס"ח סָעִיף ה'; וּלְעִנְיַן צִדּוּק הַדִּין, עַיֵּן לְעֵיל בְּהִלְכוֹת רֹאשׁ חֹדֶשׁ סי' ת"כ בְּהַגָּה, וְע"ל סִימָן תרפ"ג.
3 We do not eulogize on [these days], except for a sage in one's presence. Rema: And we do not fast for the day one's father or mother died. And a fast for a dream on Hanukkah, see above Section 568 Paragraph 5. [As regards the Justification of [Divine] Judgment [prayer], see above in the Laws of the New Moon, Section 420 in Rem"a. And see below, Section 683.]