Thirty laws pertaining to Taraweeh
1) Taraweeh follows Esha. Taraweeh is not before Esha. In a Masjid wherein Esha Jamaat is not performed, it is not valid to perform Taraweeh. (Kabiri Pg 391)
2) If a person performed Taraweeh as an Imaam or follower, he cannot again perform Taraweeh as an Imaam although he may join as a follower (with Nafl intention) in another Masjid’s Taraweeh. (Kabiri Pg 389)
3) a. To read two Rakaats with one Salaam is best.
b. To read four Rakaats with one Salaam is without objection.
c. To read eight Rakaats with one Salaam is Makrooh (detested).
d. But the reward for resting after every four Rakaats will not be obtained.
e. However, to read more than eight Rakaats with one Salaam is against the best action and Makrooh-e-Tanzihi. (Kabiri)
4) A person who enters the Masjid when Taraweeh has started, one must perform the Fardh and Sunnat then join the Taraweeh etc. (Kabiri)
5) It is permissible to perform Fardh behind one Imaam and Taraweeh and Witr behind another.
6) If the Esha Salaat was not valid due to some reason (e.g. Imaam performed it without Wudhu), then the Esha and the Taraweeh has to be repeated, although the reason for invalidity did not exist in the Taraweeh. (Kabiri)
7) All of the following intentions are valid for Taraweeh:
a. “Standing for night Salaat in Ramadhaan”
b. “of Sunnat”
c. “of the time of Salaat”
d. “of the Imaam”. (Kinayah)
8) If an Imaam is reading the second and the third section and the follower made the intention of following him in the first section, there is no problem. (Kinayah)
9) If any part of the Taraweeh was invalid or missed, then it is Makrooh to make its Qaza with Jamaat.
10) If one remembered after Witr, that a portion has been left out, this can be read in Jamaat.
11) If only 19 Rakaats were read, then two more should be read. There is no need to repeat the whole Taraweeh.
12) When repeating the two Rakaats (of those Rakaats which have been rendered invalid), the Quraan recited in those two invalid Rakaats should be repeated so that the Quraan is recited in a valid Salaat.
13) If the Imaam made 18 Rakaats and then started the Witr and then remembered that two Rakaats Taraweeh are left and makes Salaam after the second Rakaat of the Witr, it will not be counted as Taraweeh.
14) If the Imaam did not make Qa’da after the second Rakaat but did so after four Rakaats, then the later second Rakaats are counted as two of Taraweeh.
15) To read Taraweeh sitting without reason is valid, but half the reward will be received.
16) If the Imaam performed Taraweeh in a sitting position due to some reason then it is Mustahab (preferable) for the followers to stand and read.
17) To keep counting how many Rakaats have been performed is Makrooh. This is a sign of uneasiness.
18) To spend most of the night in Taraweeh is Mustahab (preferable).
19) To make one Khatam (read or listen) is Sunnat. The second Khatam is meritorious. The third Khatam is best, thus if in every Rakaat plus minus ten Aayats are read then easily one Khatam can be read and will not be difficult for the followers.
20) It is meritorious for a Hafez to return home and perform another twenty Rakaats so that he obtains the reward for two Khatams.
21) It is best to make one Khatam every ten days.
22) If the followers are so weak and disinterested, that they are not prepared to listen to the whole Quraan, with the result they discard Jamaat then read so much which pleases them or from Alam Tara. But in the above cases, they will be deprived of the reward of the Sunnat of Khatam.
23) If Aayats have been missed and whilst the Hafiz remembers those Aayats have been missed, then it is Mustahab (preferable) to read the missed Aayats and to repeat the proceeding ones.
24) It is Makrooh (detested) to leave out the small in between Surahs in Fardh Salaat but it is not Makrooh to do so in Taraweeh.
25) If the followers are weak or not energetic that they cannot bear lengthy Salaats, then after the Durood, Dua may be left out without any objection. Care should be taken not to leave out the Durood.
26) Do not read Thana when you join the Jamaat when the Imaam has started the Qiraat.
27) a. The Masbooq (one who has come late for Salaat) should not stand up quickly to complete his Salaat until he is sure and certain that the Imaam has ended his Salaat. (Muheet)
b. Sometimes the Imaam may make a Salaam to be followed by Sajda Sahwa while the Masbooq stands up the Masbooq should immediately return and join the Imaam.
28) If a person hurriedly said Takbeer while standing straight and then rushed into Ruku and his back straightened before the Imaam raised his head from Ruku then the person has got the Rakaat even if he did not say one Tasbeeh. Otherwise not. If the person did not say the Takbeer while standing straight, but said it while going into Ruku, then his start is not valid. (Muheet)
29) If one says one Takbeer as Takbeer-e-Tahrima while standing and immediately goes into Ruku to join the Imaam, it is adequate (sufficient).
30) It is permissible to read Fardh Salaat under one Imaam and Taraweeh and Witr under another Imaam. (Kabiri)
Above references (Fatawa Mehmoodia of My Ustaad Hazrat Moulana Mufti Mehmoodul Hasan Gangohi Vol 2 Pg 350 till 357)