I respect CISCE (ICSE/ISC) syllabi...and my teacher was quite competent. But then take a look here. Back in class 9 or 10 in ICSE, we had Mutli-dimensional arrays in the APC book, although it was not in the ICSE syllabus. I had made a project for ICSE which heavily relied on m-d arrays. Although my school teacher appreciated it, the external had remarked to change the project highlighting that m-d are out of scope of syllabus. I saw projects stripped down from the internet by most of my friends being awarded full marks.
I am not talking about any specific board here, I mentioned ICSE/ISC just because I belong from them. The case is true for all boards, even Prof. Madhavan Mukund regrets about it.