XQGlobalTrimNodes is true, the result of every node->string conversion is trimmed. This trimming occurs after and not during the conversion.
E.g. If it is true,
<a> a </a> return 'a', and deep-text() for
<x><a> a </a><a> b </a></x> returns 'a b'.
(This variable should actually be a property of TXQueryEngine, but that is not possible in the current design, since the values convert themself, and don't know their corresponding parser)
XQGlobalUseIDfromDTD is false, the fn:*id* functions will thus assume every attribute with name id is an ID attribute
XQGlobalUseIDfromDTD is true, only real ID attributes are used. However, simplehtmltreeparser cannot handle DTDs, so it cannot detect ID attributes. So if this is true, only the wrapped fcl-xml parser from simplehtmltreeparserfpdom can be used