A constitution may be written or unwritten, rigid or flexible. A written constitution, incorporates within its field, the principles regarding the structure of the government in the form of written documents. In the unwritten constitutions, on the other hand, the constitutional principles can be traced into the various customs and conventions and not in the written documents. No constitution exists which could be wholly written or unwritten. A written constitution might be supplemented by some conventions and usages and the British constitution which is unwritten in character has also some write documents in form of some parliamentary acts and statutes.