With the exception of unnumbered series, every CONSER RDA serial description must have numbering given in two 588 fields, the “Description based on” note and the “Latest issue consulted” note. (If the first or last issue of the serial is in hand or known, numbering is also given in field 362.)
Serial numbering may include a numeral, a letter, any other character, or the combination of these with or without an accompanying caption (volume, number, etc.) and/or a chronological designation.
Numeric and chronological information (designation and value) can be acquired from different sources and joined or pieced together to construct a complete (362) and (588) statement.
CONSER catalogers generally prefer a source with the most complete presentation of the numbering (any sequence of sequence of numerals, letters, and/or dates) provided it appears prominently or is stated formally. The lack of completeness in source of numbering information sometimes complicates the source identified in the Description based on not.
Cover (Source of title proper) has: November/December 2013; table of contents has: Volume 4, Number 6 (November/December 2013)
Record 588 as:
588 0# Vol. 4, no. 6 (November/December 2013); title from cover.