The document highlights USPS (post office) standards for mailing addresses. They require no punctuation and addresses in the USPS formatted abbreviations (ST for Street, BLVD or Boulevard). The post office uses all caps in addresses which improves delivery time using automated sorting machines.
When USPS does address validation in Gabriel, it sets the Mailing Address to all caps in the Mailing Address tab. This will not affect the address as it appears in the Family or Member Maintenance screens - just the Mailing Address tab.
For more info on USPS standards go to Publication 28, Postal Addressing Standards | Postal Explorer (usps.com)
Click here for information and a video on GabrielSoft Address Validation (Verification) Integration (found in Gabriel's help resources)