When you receive Credit you have the option to mark the person or organization who gave you the Credit as a "Trusted Issuer". You'll see the option upon initially accepting or later managing any accepted Credits. Credit received from Trusted Issuers is automatically accepted. For example, if you receive Credit from a museum you visit or a school you attend, you can set the museum or school to be "Trusted Issuers". That way, when you receive new Credit from them, you will not need to click the "Accept" button each time.
In addition, when accepting or managing Credit, you have the option to place each Credit into one or more personal categories you create. When you Trust an Issuer, you can also set the categories into which Credit from that issuer should be sorted. This makes it easy for your Credit from the museum or school to get automatically placed in your "Museum" or "Education" categories, for example. (You can later change or add categories, even for automatically accepted and sorted Credit.)
You can remove the Trusted setting from any Issuer you have previously trusted by clicking "Trusted Issuer" next to their name and then clicking the "Remove Trust" button.