The Encyclopedia of Contemporary Islam has the following 21 entries for sects, with references to other entries where relevant:
Ibāīyya, Īthnā ʿAsharīyya (see: Īmāmīyya), Amadiyya, Ismā‘īlīyya, Īmāmīyya, Bābism, Bektaşiye (Baktāshīyya), Bahāism, Tījanīyya, khujas (Ismā‘īlīyya), al-Durūzīyya, Zaidids, salfism, Shaikhīyya, ʿAlawīyya, Qadyānīyya (see: Amadiyya), Nazārids, al –Wahhabīyya.
Article Structure:
1. Title + Definition + Region of Activity
For example:
Ibāīyya (or Abāīyya): A sect of Khavārij, groups of which live in Oman and North Africa.
Ismā‘īlīyya: A Shi’i sect established in the mid-2nd century LH with its members currently spread throughout the world.
2. A brief history of the formation of a sect
3. Possible branches
4. Beliefs
5. Variety of thoughts
6. Their situation in the contemporary world
7. Geographical dispersion
8. Political influences
9. Scholars and intellectuals who belong to that sect