If you use a Microsoft Publisher address list or a Microsoft Access
database as the data source for a mail merge, filtering and sorting
are case insensitive. If you use a text file, Excel worksheet, or
most other types of files as a data source, your filtering and sorting
are case sensitive.
Case sensitivity means that lower-case letters are treated differently
than upper-case letters (usually, upper-case A-Z followed by lower-case
a-z). Case insensitivity means that both upper- and lower-case letters
are treated in the same way. For example, if you have a list that includes
the elements "Cat," "dog," "apple," and "Bat", and you sort it with a case-
sensitive sort, it will be sorted as follows:
If you sort the same list with a case-insensitive sort, it will be sorted
like this:
The address list tool in Both Microsoft Access and Microsoft Publisher
create files in the Microsoft Database (.mdb) format. This is the format
the Mail Merge database engine uses internally. Databases of other formats
are converted. Converted formats are case sensitive, while .mdb files are
not.