Name

Type

Optional

Meaning

StringExpression

String

No

String to Encode into BASE64 format

sTralingPadChar

String

Yes

Default value: "="

In Base64 encoding, the padding character "=" is used to ensure that the encoded output's length is a multiple of 4, which is necessary for proper decoding. This padding is added when the length of the input data isn't a multiple of 3 bytes.

However, some systems, such as ShippyPro's APIs, deviate from the standard by replacing the padding character "=" with a different character, like "6". This approach can be attributed to specific implementation choices or to avoid issues related to URL encoding, as the = character can have special meanings in URLs.