Always give the numbering for the earliest available issue in field 588, preceded by the words Description based on. This field must be given for all descriptions of serials even if it is the issue cited in the 362 1# and the “Latest issue consulted” note. Include the numbering of the earliest issue in hand. If there is no chronological designation, give the publishing date in addition to the numerical designation in order to supply some indication of the time frame. When a numeric designation alone is given in a "Description based on" note, add the date of publishing or copyright if possible.
588 ## $a Description based on: No. 8, published in 1990; title from title page.
588 ## $a Description based on: No. 2, copyright 1989; title from caption.
588 ## $a Description based on: 3, published 1989; title from cover?
588 ## $a Description based on print version record.