Is SPACE (%20) an unsafe meta character in URL?

What Happened?

• Is SPACE (%20) an illegal meta character in URL? 

Environment

• WAF Silverline
• WAF Policy

Resolution/Answer

 As per RFC (RFC1738)

Unsafe:

   Characters can be unsafe for a number of reasons.  The space
   character is unsafe because significant spaces may disappear and
   insignificant spaces may be introduced when URLs are transcribed or
   typeset or subjected to the treatment of word-processing programs.

Additional Information

• RFC1738: Uniform Resource Locators (URL)

Related Content

• Q&A: What are the default meta characters that are not allowed in a value for a WAF policy?
• Q&A: What are the default meta characters that are not allowed in a URL for a WAF policy?