You can exclude specific pupils from your attendance reporting by using the reporting tool found at Reporting > Reports > Attendance tab > Percentage Attendance Between:
Select the groups, forms, date range, and attendance thresholds required for your report (don't forget to include Former students if you're doing historical reporting), and then click Choose:
When the report has loaded, you can sort the table of students to display (for example) the total attendance percentage in ascending or descending order.
Just click in a free grey area of the column heading, being careful not to click the bin icon at the top (you'll have to reload the report to get the deleted column back).
Once you have your table ordered as you would like, simply locate the students you wish to exclude from the results, and then click on the student's corresponding green tick (found in final right-hand column) and this will turn the whole line grey:
If you wish to include the student once again, simply click the red X in order to toggle the student back in.
You can also exclude all Under 5s students (as attendance is not compulsory) with a simple click of the "Remove Under 5s at ..." button. Click again to toggle them back in.
When you have everything ordered and excluded as you require, you can click on the yellow Print/Download buttons in the top-right corner of the page in order to print out a physical copy of the report as it is set up on-screen, or to download a digital version as it looks in front of you.