Unused characters are padded with dots ".". The fields within the string are as follows:
| YYYY | The four digits of the year of publication |
| PUBLN | The journal code, left-justified within the five-digit field |
| The codes for those journals regularly entered into NED are: |
| A&A.. | Astronomy and Astrophysics |
| A&AS. | Astronomy and Astrophysics Supplement Series |
| AJ... | Astronomical Journal |
| ApJ.. | Astrophysical Journal |
| ApJS. | Astrophysical Journal Supplement Series |
| ARep. | Astronomy Reports (formerly Soviet Astronomy) |
| AstL. | Astronomy Letters (formerly Soviet Astronomy Letters) |
| Ast.. | Astronomy |
| IAUC. | IAU Circulars |
| MNRAS | Monthly Notices of the Royal Astronomical Society |
| Natur | Nature |
| PASP. | Publications of the Astronomical Society of the Pacific |
| PASJ. | Publications of the Astronomical Society of Japan |
| VVVV | Volume number of the journal, right-justified within the four-digit field |
| M | Tie-breaker code. Where ambiguity is possible (e.g. between the main journal section, |
| and the "letters" section of a journal), the following characters or digits in this field break the ambiguity: |
| L | Letters sections in various journals |
| p | Pink pages in MNRAS (changed to "L" in 1993) |
| 1, 2, ..., 9, | Issue numbers 1 through 0, then "a" through "o", within the same volume of a journal |
| 0, a, b, c, | (e.g. Sky and Telescope, Physics Today) |
| ..., o | |
| A, B, ... | Issue designations used by the publisher within the same volume, where each issue starts with page one |
| OR | |
| Two or more articles appearing on the same page within a single issue of a journal | |
| (e.g. Nature, IAU Circulars) are lettered successively beginning with A - Z |
| PPPP | Starting page number of the article, right-justified |
| A | First letter of the first author's last name, or a ":" when no authors are specified for a reference |
More information on reference codes is available in a paper by members of the NED and SIMBAD groups.
Similarly, we add "NOTES01" to UGC 01562 to refer to a galaxy included only in the UGC Notes for UGC 01562.
We typically use the "ID" suffix to indicate that a non-optical source (e.g. an infrared source) has been associated with an otherwise unnamed physical object, usually a galaxy. An example is "IRAS 00182+1130". This has been identified as a galaxy, but not given a separate name. The "ID" notation makes it clear that the object has been reclassified from its original type.
Other suffixes that we use include "COM" for a nearby companion, not necessarily physically connected to the main object (e.g. "3C 227 COM01"), "ABS" for an absorption line system seen along the line of sight to a background object (e.g. "[HB89] 1727+502 ABS01"), and "ARC" for gravitationally-lensed arcs usually found in rich clusters (e.g. "ABELL 0164 ARC01").
There are three basic categories of names presently in use.
The "acronym" should be one which makes sense for your program so that future researchers can easily recognize the origin. For example, the acronym could be the last-name initials of the first few authors, or an imaginative scheme to indicate how or why the objects were discovered. You should be sure to clearly define the acronym in your paper. You may also register the acronym with the IAU at the CDS site Proposal for Registering a New Acronym.
Coordinate-based names may be based on B1950 or J2000 coordinates. If the latter, a "J" must precede the name. For example, a galaxy with J2000 (or ICRS) coordinates of 12h 34m 56.7s, +76d 54m 32s would be given a name like "GALCAT J123456.7+765432". Note that coordinate-based names without a leading "B" or "J" are ALWAYS interpreted as B1950, NOT J2000.
Whatever name you choose for your objects, it is vital that you include coordinates for the objects to insure that other observers can locate them on the sky. Positional uncertainties are helpful, too.