1. Add custom attribute to the richtext editor as follows:

ezplatform:
    system:
        admin_group:
            fieldtypes:
                ezrichtext:
                    attributes:
                        embed:
                            my-attribute:
                                type: choice
                                choices: [attributefoo, attributebar]
                                default_value: attributefoo
                                required: false
                                multiple: false

2. Edit Content and embed another Content Object
3. Edit Attribute and set value to attributefoo
4. Publish Content
5. Search for attributefoo

Result:
Search finds the previously changed Content

Expected:
Search should not find the previously changed Content, as information is not supposed to be "content"
(Note:  in some usecases it might be expected behavior that custom attributes can be found - so ideally it should be possible to control this behavior per attribute)