Why is the Jazariyyah Poem considered as an important reference for the students of tajweed, whereby, it does not cover all the rules of tajweed?

Question
Assalamualaikum

Why is the Jazariyyah Poem considered as an important reference for the students of tajweed, whereby, it does not cover all the rules of tajweed?

For example, I could not find the explanation of the Lam Sakinah in the poem.

Is it sufficient to study the poem to have a good knowledge of tajweed?

Jazakallahu khairan.

Answer
Wa alaikum assalaam wa rahmatullahi wa barakaatuh
The basic rules for recitation are found in the Jazariyyah poem for tajweed.  Most of the laam saakinah rules are there but not in a specific section.  For example he states:

This covers all the basic laam saakinah rules.  Many of the early scholars would use the term mutajaanis or mutaqaarib interchangeably for both the similar ( ) and the close ( ) in relationship between two letters.  So if there is a laam saakinah  at the end of a word, and after it a letter mutajaanis (meaning mutaqaarib) or mithl (meaning the exact same letter), between two words, the general rule is idhgham and the examples he gave, rahimahu Allah are both of the laam saakinah. 
The lam shaamsiyah letters all are mutaqaarib  with the except if a follows the of ta'reef, then it is
The lam of the participle and merges into the first letter of the next word if it is mithl (the same letter) or mutaqaarib (mutajaanis).  The same with verbs ending with a saakinah. 
If you want to be able read the Qur'an correctly, it is sufficent as a guideline. for the rules.  If you want to study to a higher level and get an ijaazah in the recitation by memory, more details would be needed to be absorbed and there would be some other subjects which would need to be studied.  Remember, the learning poems are meant to help keep the material in a brief form and easy to recall, but studying the poems in depth with explanation should be done at the hands of a scholar. 
Wa iyyaakum