In the following HTML page:
http://www.postgresql.org/docs/user/typeconv.htm#AEN1886
The following text is displayed (second paragraph):
In many cases a user will not need to understand the details of the
type conversion mechanism.
However, the implicit conversions done by Postgres can affect the
apparent results of a query, and
these results can be tailored by a user or programmer using explicit
type coersion.
The last word of this paragraph is, I believe, mispelled. It should be
"conversion" not "coersion".
...james