On some drawings and plans you can use an arrow to identify the location and/or direction of the specific item if necessary. Some common drawing cross-reference examples are shown below.

Australian Standard

Special area reference

Areas on location drawings that require additional information should be cross-referenced to special area drawings by the use of the cross-referencing symbol. The upper segment of the circle contains the room number or area code, and the lower segment has the special area drawing number (or sheet reference/number) in it, as shown below.

What is semantic for the "equation"? - Alfred

Drawing or detail number
on
Special area drawing or sheet number/reference
The symbol for a special area reference

Elevation reference

Location drawings can be coded to identify specific elevations, and cross-referenced to elevation drawings by the use of the cross-referencing symbol. This symbol may be used independently, or in conjunction with an orientation reference such as North elevation.

As per the example shown below, for this one the upper segment of the circle should contain the block code and the sequential elevation number for the block, and the lower segment of the circle has the elevation drawing number (or sheet reference/number) in it.

Elevation reference (may include 'E')
on
Drawing or sheet reference/number
The symbol for an elevation reference

Cross-section reference

Location drawings should be coded to identify specific cross-sections, and cross-referenced to the section drawings by the use of the appropriate symbol. As shown in the example below, the upper segment of the circle contains the block code and the sequential section number for the block, and the lower segment holds the section drawing number (or sheet reference/number).

Block code + section sequential number)
on
Section drawing (number)
The symbol for a cross-section reference

For clarity, 'S' may be included in the section designation.

Detail reference

Location drawings should be coded to identify specific positions where detailed construction information is required, and cross-referenced to construction or assembly detail drawings. For this symbol the upper segment of the circle contains a sequential detail number, and the lower segment contains the specific detail drawing number (or sheet reference), as shown in the example below.

Detail sequential number
on
Drawing/sheet reference number
The symbol for a detail reference

Reproduced under copyright licence from SAI Global.