As a professional you must know 

1 The Five Laws of Library Science  

• 1. Books are for use. 
• 2. Every book its reader. 
• 3. Every reader his/her books. 
• 4. Save the time of the reader and the staff. 
• 5. Library is a growing organization. 
•                              Dr. S. R. Ranganathan

2 The Five Laws of the Web

1. Web resources are for use.
2. Every user his or her web resource.
3. Every web resource its user.
4. Save the time of the user.
5. The Web is a growing organism.

                                         Alireza Noruzi 
  3  Five laws of librarianship:

1. 1. Libraries serve humanity.
   2. Respect all forms by which knowledge is communicated.
   3. Use technology intelligently to enhance service.
   4. Protect free access to knowledge; and
   5. Honor the past and create the future  

                                              Crawford & Gorman