[BRLTTY] What do this entries mean?

[Hermann]

Hi,
during the boot procedure, there appear a lot of entries in
/var/log/boot regarding the start up of brltty.
They seem to indicate that a large bunch of entries in my Geman
braille table file are not recognized by the program.
I report a few essential lines:

Thu Aug 21 17:31:34 2008: brltty[3552]: /etc/brltty/de.ttb[23]: unknown text table directive: <<<<<<<
Thu Aug 21 17:31:34 2008: brltty[3552]: /etc/brltty/de.ttb[24]: unknown text table directive: \X00

It goes on dozens of lines counting up the hexadecimal figures.
What does this mean, and why does it appear?
Hermann

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