Styles and display settings in project standards drawings and project drawings have a version. The version is used to determine whether a style or display setting needs to be synchronized. The version information includes a unique GUID (Global Unique Identifier), the date and time of the last modification, the Windows login name of the user who last modified the object, and an optional comment.
When a project is audited or synchronized with its standards, the comparison of the versions determines whether styles and display settings in the project are identical, older, or newer than the project standard.
Styles or display settings are considered identical to the project standards if the following are identical:
For determining whether a style in a project drawing is identical to a project standard style, the GUIDs of both are compared. The GUID is a unique string that is newly created for each version of a standard object. In the project standards drawing, a list of previous GUIDs is kept as a version history to enable comparison with objects in a project drawing.
If the synchronization process finds a style or display setting in a project drawing that has the same type, name, and version GUID as the corresponding style or display setting in the project standards drawing, it concludes that the style or display setting is a standard one, and in synch with the object in the project standards drawing. In that case, no change is necessary.
If the comparison finds that the GUID in the project drawing does not match the GUID of the style in the project standards drawing, but matches a previous GUID from the standard style version list, it labels the style in the project drawing an “older version of a standard style.”
If the comparison finds a style or display setting that matches a standard object in name and object type, but has a GUID not appearing in the version history of the standard style or display setting, the style or display setting in the project drawing is labeled “nonstandard (newer) version of standard object.”
A new version of a standard style or display setting in a project drawing is created automatically each time the style or display setting is changed in Style Manager or Display Manager.
A new version of a standard style or display setting in a project standards drawing must be created manually when the style or display setting is changed in Style Manager or Display Manager. In project standards drawings, a version history for each standard style and display setting is also stored. The version history is used during synchronization to determine if styles or display settings in project drawings match the versions in the project standards drawing, or are newer or older versions.
There are a few cases where modifications to the display settings will not be automatically versioned, as this will in most use cases not be a desirable effect. Some settings will routinely vary from the standards drawing, so these settings will not be included in the automatic versioning process.
Standard styles and display settings in project standards drawings contain a version history for changes made to them during the project. You cannot roll back to a previous version of a standard object. The version history is only used to determine the current state of standard styles and display settings.