Yes. In the past, when subject headings have been limited to two or three cards, subject analysis has been carried out at the summarization level. Depth indexing has been limited to the realm of periodical indexes, abstracts, and certain bibliographies. With the automation of the catalogue it is no longer necessary to limit subject headings to the summarization level.No. In the past, when subject headings have been limited to two or three cards, subject analysis has been carried out at the summarization level. Depth indexing has been limited to the realm of periodical indexes, abstracts, and certain bibliographies. With the automation of the catalogue it is no longer necessary to limit subject headings to the summarization level.No. In the past, when subject headings have been limited to two or three cards, subject analysis has been carried out at the summarization level. Depth indexing has been limited to the realm of periodical indexes, abstracts, and certain bibliographies. With the automation of the catalogue it is no longer necessary to limit subject headings to the summarization level.