- the record document for the request. If doc is a quoted string
- (double quotes) the string content is used verbatim. If doc is not
- a quoted string, it is assumed to be a filename which is read, then
- sent as the docuemnt content. If doc is omitted, the last received
- record (as parf of present response or piggybacked search response)
- is used for the update.
+ the record document for the request. If doc is preceded with
+ "<", then the following characters are treated as a filename
+ with the records to be updated. Otherwise doc is treated as
+ a document itself. The doc may also be quited in double quotes.
+ If doc is omitted, the last received record (as part of present
+ response or piggybacked search response) is used for the update.