Add an FAQ.
diff --git a/FAQ b/FAQ
index 6c07b69..c492c09 100644
--- a/FAQ
+++ b/FAQ
@@ -70,6 +70,7 @@
* I think I've detected a memory leak, is this a bug?
* Why does Valgrind complain about the use of uninitialized data?
* Why doesn't a memory BIO work when a file does?
+* Where are the declarations and implementations of d2i_X509() etc?
===============================================================================
@@ -967,4 +968,15 @@
See the manual pages for more details.
+* Where are the declarations and implementations of d2i_X509() etc?
+
+These are defined by macros of the form:
+
+
+ DECLARE_ASN1_FUNCTIONS(X509) and IMPLEMENT_ASN1_FUNCTIONS(X509)
+
+The implementation passes an ASN1 "template" defining the structure into an
+ASN1 interpreter using generalised functions such as ASN1_item_d2i().
+
+
===============================================================================
