There are five reports TRIGGER with order:

1. Before Parameter Form
2. After Parameter Form
3. Before Report
4. Between Pages
5. After Report

Before Form Trigger: It wills Fires before the Run time Parameter Form that will displayed on screen. By using this trigger you can change the value of the parameters.
After Form Trigger: Fires after the Run time Parameter Form is displayed. From this trigger, you can access parameters and check their values. This trigger can also be used to change parameter values or, if an error occurs, return to the Runtime Parameter Form.
Before Report Trigger: It will Fires before the report is executed but after queries are parsed and data is fetched.
Between Pages Trigger: Fires before each page of the report are formatted, except the very FIRST page. This trigger can be used for customized page formatting. (Note: In the Previewer, this trigger only fires the first time that you go to a page. If you subsequently return to the page, the trigger does not FIRE again.)
After Report Trigger: Fires after you exit the Previewer, or after report output is sent to a specified destination, such as a file, a printer, or an Oracle*Mail userid. This trigger can be used to CLEAN up any initial processing that was done, such as deleting tables. Note, however, that this trigger always fires, whether or not your report completed successfully.

Format Triggers: Format Triggers are PL/SQL functions executed before the OBJECT is formatted. The trigger can be used to dynamically change the formatting attributes of the object.

There are five reports trigger with order:

Before Form Trigger: It wills Fires before the Run time Parameter Form that will displayed on screen. By using this trigger you can change the value of the parameters.
After Form Trigger: Fires after the Run time Parameter Form is displayed. From this trigger, you can access parameters and check their values. This trigger can also be used to change parameter values or, if an error occurs, return to the Runtime Parameter Form.
Before Report Trigger: It will Fires before the report is executed but after queries are parsed and data is fetched.
Between Pages Trigger: Fires before each page of the report are formatted, except the very first page. This trigger can be used for customized page formatting. (Note: In the Previewer, this trigger only fires the first time that you go to a page. If you subsequently return to the page, the trigger does not fire again.)
After Report Trigger: Fires after you exit the Previewer, or after report output is sent to a specified destination, such as a file, a printer, or an Oracle*Mail userid. This trigger can be used to clean up any initial processing that was done, such as deleting tables. Note, however, that this trigger always fires, whether or not your report completed successfully.

Format Triggers: Format Triggers are PL/SQL functions executed before the object is formatted. The trigger can be used to dynamically change the formatting attributes of the object.