Q: Is there a preferred way to define "hidden" volumes in HFS (i.e., the way AOCE declares "Mail Enclosures", etc.)?

A: AOCE's Mail Enclosures volume is hidden because its root directory has the kIsInvisible Finder flag set. You can use the SetIsInvisible routine in the MoreFiles DTS sample code to make the root directory of a volume invisible, so the next time the volume is mounted, the Finder doesn't show that volume. There is no way to force the Finder to notice the change and make the volume invisible on the fly.

Note that the Finder did not support invisible volumes until System 7 Pro (System 7.1.1). Therefore, with System 7.1 and earlier versions, you can't make volumes invisible. The SetIsInvisible function can be found in the MoreFilesExtras.c file at the following path on the Developer CD:

Dev.CD Feb 95:Sample Code:MoreFiles 1.2.1:MoreFilesExtras.c

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