--- code/trunk/doc/pcrebuild.3	2007/02/24 21:40:03	63
+++ code/trunk/doc/pcrebuild.3	2007/02/24 21:40:30	73
@@ -106,7 +106,40 @@
 using UTF-8) will fail. Part of the output of these tests is a representation
 of the compiled pattern, and this changes with the link size.
 
+.SH AVOIDING EXCESSIVE STACK USAGE
+.rs
+.sp
+PCRE implements backtracking while matching by making recursive calls to an
+internal function called \fBmatch()\fR. In environments where the size of the
+stack is limited, this can severely limit PCRE's operation. (The Unix
+environment does not usually suffer from this problem.) An alternative approach
+that uses memory from the heap to remember data, instead of using recursive
+function calls, has been implemented to work round this problem. If you want to
+build a version of PCRE that works this way, add
+
+  --disable-stack-for-recursion
+
+to the \fBconfigure\fR command. With this configuration, PCRE will use the
+\fBpcre_stack_malloc\fR and \fBpcre_stack_free\fR variables to call memory
+management functions. Separate functions are provided because the usage is very
+predictable: the block sizes requested are always the same, and the blocks are
+always freed in reverse order. A calling program might be able to implement
+optimized functions that perform better than the standard \fBmalloc()\fR and
+\fBfree()\fR functions. PCRE runs noticeably more slowly when built in this
+way.
+
+.SH USING EBCDIC CODE
+.rs
+.sp
+PCRE assumes by default that it will run in an environment where the character
+code is ASCII (or UTF-8, which is a superset of ASCII). PCRE can, however, be
+compiled to run in an EBCDIC environment by adding
+
+  --enable-ebcdic
+
+to the \fBconfigure\fR command.
+
 .in 0
-Last updated: 21 January 2003
+Last updated: 09 December 2003
 .br
 Copyright (c) 1997-2003 University of Cambridge.