In this chapter, we will cover the following recipes:

• Preventing non-system administrators from changing account names with a validation rule
• Enforcing the use of two-letter account country codes using a validation rule
• Validating if US zip codes are well-formed using a validation rule with REGEX
• Validating if UK postcodes are well-formed using a validation rule with REGEX
• Creating a mandatory reason lost field for lost opportunities using a validation rule
• Blocking excluded countries with a custom country object and VLOOKUP validation rule