Final answer:
The flag flown on Sundays and holidays, measuring 20x38ft, is called the Garrison flag. It represents the presence of a commanding officer or a high-ranking official.
Step-by-step explanation:
The flag flown on Sundays and holidays, measuring 20x38ft, is called the Garrison flag. This flag is typically flown on special occasions and represents the presence of a commanding officer or a high-ranking official. It is larger than the regular post flag or storm flag and is used to convey authority and significance.