What is the importance of BS 8888 general principles in engineering drawing?

It is always better to make the drawings as per some recognized standard. The engineering drawings normally use letters, symbols and short forms to make the drawing more readable. To avoid any confusions to an external party (a component supplier company - it could be even from Another Country, or even the customer) regarding the meaning of these symbols, notations short forms etc. also making a standardized format for drawings make it easy for anyone to understand the drawing. They can easily understand where to look for the Title block, Notes general tolerances etc.