Hi,
This may be a question for upstream rather than debian, but I thought I
would start here to see if anyone was aware of this issue or had dealt
with it previously.
At a number of places in the source code for postgis, reference is made
to the comp.graphics.algorithm FAQ [1].
As an example, see the comments at [2]. This appears to be a fairly
direct lifting of text from the FAQ, a document which a Joseph O'Rouke
is (claims to be?) the author of. It appears that redistribution of that
document in its entirety is permitted, however nothing is said about partial
extracts.