Anchoring Objects In Oracle Reports.

An anchor defines the relative position of an object to the object to which it is anchored. Anchors are used to determine the vertical and horizontal positioning of a child object relative to its parent. Since the size of some layout objects may change when the report runs (and data is actually fetched), you need anchors to define where you want objects to appear relative to one another.

There are two types of anchors in Oracle Reports:
* implicit (anchors that Oracle Reports creates when a report is run)
* explicit (anchors you create)

Implicit Anchors : At runtime, Oracle Reports generates an implicit anchor for each layout object that does not already have an explicit anchor. It determines for each layout object which objects, if any, can overwrite it, then creates an anchor from the layout object to the closest object that can overwrite it. This prevents the object from being overwritten. The implicit anchor functionality saves you from having to define the positioning of each object. Implicit anchors are not visible in the Layout editor. However, you can specify that the Object Navigator display anchoring information using the Object Navigator Options dialog.

Explicit Anchors : Create an anchor in the Layout editor by clicking on the Anchor tool, dragging from one edge of the child to the one of the parent’s edges, then specifying the anchor’s properties in its property sheet. Any anchor you create for an object will override its implicit anchoring. Explicit anchors are always visible in the Layout editor unless you specify otherwise via the Layout Options dialog

Read the reports 6i user guide for clear information.