*.BLL files. What are these?

Hello,

I write the database Application with the Paradox tables. When I create
the distibution disks of my Application with help The InstallShield Express
(Delphi Edition), it automatically appends the Group 'BDE/IDAPI BLL files',
which consist of following files:
                                   USA.BLL,
                                EOROPE.BLL,
                              CEEOROPE.BLL,
                               CHARSET.BLL,
                                 OTHER.BLL.
I use the 'Pdox ANSI Cyrilic' language only in my Paradox tables.
          ----------------------------

I know, that is the language driver.

Who knows, what are doing *.BLL files ?
Can I don't use all these files, or some of these only ?
Where I can found the information about these files ?
What are names of the newsgroups about The InstallShield ?
What are difference between The InstallShield Express and The InatallShield 3?

Please send me answers.
Thank you.
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Eugene Kovalov                  e-mail r...@kovalev.dp.ua