The “Bookmark” option is present both in advanced and preset reports. It enables to create custom reports to program the delivery via email.
Creation of Advanced Bookmark Reports
...
...
In order to create Preset Bookmark Reports, access the list of preset reports. Then, select the report you wish to save, and finally click on 'Bookmark'. A window will pop up to name the report. The page will change and the report saved will be displayed in the list below under the selected name, as well as the ones you may eventually configure.
Bookmark Reports via email programming
In order to set Bookmark Reports via email, access Reports via email within User Preferences and set the day/days the bookmark report needs to be sent.
...