To Add a Model Signature

From the Digital Signatures dialog, select the Place Signature Cell icon.
The Place Signature Cell dialog opens. This tool is used to place a model signature that applies to and displays in the current model.
Select the cell library that contains the signature cell with the Attach Signature Cell Library tool.
The Cell field will be populated with a list of available signature cells from the currently attached signature cell library.
Choose a signature cell from the Cell pull-down menu.
Enter the angle by which the cell is rotated in the Active Angle field.
Enter the scale at which the cell will be placed in the Scale field.
(Optional) Check the Include Reference box to include all attached references in the signing.
(Optional) Enter the name of the person signing the model in the Signer field.
The Signer defaults to the current user’s login name.
(Optional) Enter a description of the signer’s intent.
(Optional) Enter a date that the signature expires.
Check this option to make the new signature depend on all signatures that are currently selected in the Digital Signatures dialog.
This check box is disabled if no signatures are selected.
Click a data point to place the signature cell.
The new signature displays in the current model of the DGN file and appears in the Signature dialog.

Note: A red seal next to the signature in the model indicates that it is a signature. Moving or modifying the signature invalidates the signature. An invalid signature is displayed with a red X across it. A yellow warning symbol is displayed if the signature is based on a certificate that is not trusted or if the signature has expired.