base_64 encoding

According to Faq-O-Matic:

The command slappasswd -h {SHA} -s abcd123 will generate {SHA}fDYHuOYbzxlE6ehQOmYPIfS28/E= so, in your entry, an attribute like this could be specified: userPassword: {SHA}fDYHuOYbzxlE6ehQOmYPIfS28/E= but when you do a slapcat or ldapsearch and the output is in LDIF format, the userpassword will be base_64 encoded, and it will look like this: userPassword:: e1NIQX1mRFlIdU9ZYnp4bEU2ZWhRT21ZUElmUzI4L0U9

Just out of curiosity why is it further encoded as everything in the userPassword is already base_64 encoded except the string {SHA}? I thought it may be because of the brackets but putting brackets in another attribute (e.g. mail) doesn't trigger an encoding.

Regards, Thierry.