What is the tenth principle?

Salam wa rahmah
 
In your introduction you say that there are only 9 principles, however I have learnt according to the poem that there are 10.
 
1. Al hadd
2. almawdhu'
3. Ath-thamar
4. fadhlu
5. nisba
6. waadhi'
7. Al'ism
8. Alistimdad
9. Hukm Shari'
 
What is the tenth, can you please clarify?

Answer:

 Wa alaikum assalaam wa rahmatullahi wa barakatuh,
 
You are correct, we only posted nine of the ten principles laid out for all forms of Islamic knowledge.  We did not say that there were only nine, but should have put the tenth too.  We do not recall now our reason for not putting up the tenth.  The poem lines are:

The 10th principle that is missing from the principles section on the site is , which means issues.  In the explanation in the book “Hilwatu At-Tilaawah fee Tajweed al-Quran al-Kareem” by Dr. Rehab Shaqaqi, under the supervision of Dr. Ayman Swayd, the are explained as:
 
1. Knowledge of the articulation points of the letters
 
2. Knowledge of the inherent characteristics of the letters.
 
3. Knowledge of what becomes needed in rules because of the order of letters.
 
4. Exercising the tongue and much repetition.
 
Wa assalaam