Custom lists are useful in reports
You can use your custom lists to filter the amount of data that will appear on your custom reports. For example, you could use data from a custom item list to formulate an stock report showing only items that are available at a certain warehouse location. Every custom list that you have defined will appear in the Report Customisation window for each report on which those lists can be used. To filter your report data using custom list criteria, choose the appropriate item from each custom list that you want to use as a filter.
When you specify a particular list as a report filter, only the records that contain the type of data specified in that list will appear in the report. If you don't specify custom list data for a report, the report will include all records that meet all of the other criteria you have specified; your custom list entries will not be considered when the report is formulated. If you specify report filters from more than one custom list, the report will include only those records that contain data in all of the lists.
You can also show custom list data for every record in a report, even if you don't use the lists to filter records in that report. If you want custom list data to appear on a report, use the Report Customisation window to select the custom lists that you want to display.