There are 35 different Building Block Types but the ones most commonly used
are the equivalent of formatted AutoText entries. They are essentially
stored in what can be referred to as a "Library". From that library each can
be inserted into documents as frequently as necessary.
When you insert them into a document, however, their *content* is simply
copied into the document. At that point it becomes content just like any
other content typed or inserted into the document. IOW, the Building Block
isn't moved into the doc as a Building Block item.
The answer to your question is that any docs created on your PC which have
content derived form Building Blocks will still have that content if moved
to a Mac. Opening that doc in Mac Word, however, doesn't teleport the
Building Block to the program - the presence of the content doesn't enable a
non-existent feature in the program.
Depending on the Building Block Type you can then select that content on a
Mac & create an AutoText Item or add it to the Scrapbook. Then you can
continue to repetitively insert it into other docs. Info on both is
available in Word Help.
HTH |:>)
Bob Jones
[MVP] Office:Mac