I think "standing in the sun" punishment was conceived by Kamakshi, the mother of Maya, and also the mother of most diabolical punishments in the school. It was usually awarded if the whole class was responsible for something. Like, if the students of a class were late to "form" the assembly line, or were late by a few mins to the class.
As kids nobody felt bad about the punishment. At least I thought it was better than sitting in the class at that time. When sympathetic teachers would stand with us, we would tell them, "We are getting Vitamin D".
But later on you realize how sadistic that punishment was.
As principals, they tried to get respect through fear. Which I think was the worst example to set for the students, something which could have scarred them more than any punishments.
We had to chant the entire "Sahasranamam" on Thursday mornings, new practice that was introduced after Swami Chinmayananda, passed away. I used to volunteer for "minding" the lower classes because it was better than sitting crosslegged and chanting things that didn't make any sense.
One day, I saw my classmate, Harikrishna who was in the adjacent room, send Maya's daughter out of the class. "She was not behaving herself" he told me. Unfortunately for him, Maya was doing rounds in that corridor at that time and when she saw that her daughter was standing outside the class, she got really pissed off, asked her daughter to go into the class and summoned Harikrishna to her room where he was caned.
Another punishment was to 'run 5 times around the school ground' if you were late. This was not so bad because it was at least healthy but I would tell the P.T master that I had asthma and excuse myself from it.
We had a school diary which had just 2 places for recording late arrivals to schools. Obviously, the school underestimated the traffic situation and a slew of things that can delay things in India. The wily principal thought of this as a business opportunity and said that if you don't have a place to record the late arrival, you must buy a new diary.
When we were at 11th std, she came to know that everyone was attending tuitions and classes for Engineering/Medical entrance exams. But this was at odds with her focus on getting higher marks in the Board exams which determined the reputation of the school. So one day in the assembly, she announced a ban on attending any outside tuition. Of course the ban didn't work.
Then, she had an idea: If the students want to attend tuition, why can't the school give the tuitions after class? But the clever part was that it was not going to be free and there would be a fee of Rs.1000 for the tuitions.
Nobody joined the internal tuitions and then, she held a parent meeting which failed miserably because after that meeting, she never mentioned about it.
I know that there are worse schools but what is sad was that Maya was awarded "the best principal" award some years back. Its all an illusion.

