## Scan: Values of Position-in-response

Issue raised by: Emily Koechlin, 24 Aug 1995

Synopsis:
What are the semantics of values of Position-in-response outside the range of 1 through N, where N is Number-of-entries (i.e. zero, negative values, values greater than N).

Response:
The semantics of these values are mathematically consistent with values in the range of 1 through N.

The semantics of the Position-in-response parameter are illustrated by the following example: a term list includes consecutive terms A, B, C, D, E, and F; the Scan Request specifies C as the starting term, and 2 for Number-of-entries.

If the value of Position-in-response is 1, then C is to be the first of the terms returned; terms C and D are to be returned. If the value of Position-in-response is 2, then C is to be the second of the terms returned; terms B and C are to be returned. If the value of Position-in- response is 3 (and thus greater than Number-of-entries), then C is not to be returned (because it is the third term and only two terms are to be returned); terms A and B are to be returned.

If the value of Position-in-response is zero, then C is not to be among the terms returned. (This is because within the list of potential terms to be returned, the ordinal value of the first term to be returned must be 1. But the ordinal value of C is zero, as specified by Position-in- response. Thus C preceeds the first term to be returned.) Terms D and E are to be returned. If the value of Position-in-response is minus 1, then terms E and F are to be returned; etc.

Note that describing the semantics does not mean that a target must support these values: a target may always indicate non-support for a value of Position-in-response by supplying bib-1 diagnostic 233.

Status: Approved (2/96)
Library of Congress
Library of Congress Help Desk (04/10/96)