A VAT number!

After breaking it down:

* 2005 is the calendar year
* 86 is the registration number ( assigned to a specific business in South Africa)
* 0796 is the branch number (not applicable in all cases, but present here)
* 100058 is the tax type and payer code (in this case, likely a company)

However, I couldn't pinpoint the exact location or type of business with certainty. If you need to verify this VAT number for a specific purpose, it's best to check with SARS (South African Revenue Service) directly.

Would you like me to try and find more information about this VAT number?