853-855 Subfield $y - Regularity pattern:

Subfield $y contains codes that describe the regularity of the publishing pattern coded in subfield $w (Frequency).  The subfield may be structured as either a chronology type or enumeration type.  Both types begin with a publication code.

Publication Code:

The first one-character code in both the chronology type and enumeration type indicates whether the subsequent codes refer to the publication or the nonpublication of part(s) of the item or the combination of either enumeration or chronology elements.

c - Combined

o - Omitted

p - Published

Chronology Type:

The chronology type of regularity pattern is structured as:

<Publication Code><Chronology Code Definition><Chronology Code>,<Chronology Code>,...

The subfield may contain one or more chronology codes that are associated with the publication code and chronology code definition that are in the first and second character position of the subfield.  The subfield may be repeated to allow for coding more than one publication code/chronology code definition/chronology code string to indicate regular exceptions to a specified regularity pattern (i.e. normalized irregulars).

Chronology Code Definition - The second one-character code in the subfield indicates whether the subsequent Chronology Code(s) represent the name of a day, a numeric month or month and day code, a code for a season of the year, or a code for a week of the month or year.  If the subfield describes regularity in terms of enumeration, this code is "e."

d - Day

m - Month

s - Season

w - Week

y - Year

Chronology Code - The chronology code in the chronology type indicates the designation of the part of the item for which regularity pattern information is provided.  Multiple codes are separated by a comma.  A slash ( / ) is used to designate combined issues.

Two-character alphabetic or numeric codes are used for days, weeks, months, and/or seasons.  A four character code is used to indicate the year or year combination.  A code of less than two digits is right justified and the unused position contains a zero.

Examples:

854  03  $81$a(year)$b(month)$c(day)$wd$yodsa

[Item is published daily except Saturday.]

854  02  $81$av.$bno.$u11$vr$i(year)$j(month)$wm$x01$ycm07/08

[Item is a monthly, with the first number appearing in January and a combined July/August issue.]

854  03  $81$av.$bno.$u10$vr$i(year)$j(month)$wm$x09$yom07,08

[Item has ten numbers per volume; ten numbers per year beginning with no. 1 in September; no numbers published in July or August.]

854  23  $81$av.$bno.$u3$vr$i(year)$j(season)$w3$x21$yps21,22,23

[Item has three numbers per volume; three numbers per year, published in Spring, Summer, and Autumn.]

853  03  $81$av.$bno.$u43$vr$i(year)$j(month)$k(day)$w43$x0901$yow0604we,0702we,0703we,0704we,0802we,0803we,0804we,0805we,
1203we,1204we,1205we$ypdwe

[Item has weekly issues except on dates noted in subfield $y.]

863  30  $81.1$a21-22$i2001-2003

863  41  $81.2$a23$b1$i2003$j09$k03

853  20  $81$av.$bno.$u48$vr$ww$x0101$yow05we

[Item is a weekly, but omits the fifth Wednesday of the month.]

853  03  $av.$bno.$u12$vr$i(year)$j(month)$wm$x01$ypw02we$ypw0402th,0501we$yow0402we,0502we

[Item is monthly, published every second Wednesday of the month except in April when it is published on the second Thursday and May, when it is published on the first Wednesday.]

853  02  $av.$bno.$uvar$vr$i(year)$j(month)$k(day)$wc$x07$ypw00mo,00th$yod0101,0704,1225$yow0901mo,1104th

[Item is published every Monday and Thursday except for when New Years Day, the fourth of July, Labor Day, Thanksgiving and Christmas fall on a Monday or Thursday.]

853  02  $av.$i(year)$wg$ypyyyy1/yyy2

863  41  $a10$i1999/2000

[Item is published every other year combining chronology to reflect the span of coverage.]

Enumeration Type:

The enumeration type is structured as:

<Publication Code><Enumeration Code Definition><Enumeration Code>,<Enumeration Code>,...

An enumeration code may occupy the second and third positions after subfield $y to provide for regularity patterns for items that use only enumeration for sequencing and/or those items whose sequencing must be specified separately when combinations occur.

Enumeration Code Definition - The second code in the subfield indicates whether the subsequent codes represent enumeration rather than chronology.  When code "e" is used, an additional numeric code is added to indicate the level of enumeration to which the regularity applies.

e1 - Enumeration, 1st level

e2 - Enumeration, 2nd level

Enumeration Code - The enumeration code following the enumeration code definition indicates the designation of the issues of the item for which regularity pattern information is provided.  Multiple designations are separated by a comma.  A slash ( / ) is used to designate a combined issue.

Example:

853  02  $81$av.$bno.$u6$vr$ws$x01,02,03,04,05,06,07,08,09,10,11,12$ypw02we,04we$yce21/3,4/6

[Item is published twenty-four times per year on the second and fourth Wednesdays of every month.  The second level of enumeration combines numbers 1 to 3 on the second Wednesday of every month and numbers 4 to 6 on the fourth Wednesday of every month.]

The presence of continuous numbering ( subfield $v, code c) in conjunction with an enumeration code signals the combination of specific numbers in the sequence of specific issues.  Because of the continuous numbering, the actual enumeration values cannot be used to express the enumeration in subfield $y.  Enumerative values must be represented in terms of the number of issues expected to be published to allow combined issue prediction to occur.

Examples:

853  02  $81$av.$bno.$u52$vc$ww$yce251/52

[Item is published weekly except for a combination in the last two weeks of December.  Since issue description is limited to enumeration only, and the second level enumeration is also continuous, the pattern represents the issue combination in terms of combining the fifty-first and fifty-second issues published that year.]

853  20  $81.0$a(year)$b(month)$c(day)$ww$ycw1203/1204

[Item is published weekly except that it combines the third and fourth weeks in December.]

Automated systems may construct algorithms to predict the second level of continuous enumeration based on the starting value of the second level of enumeration at the beginning of the subscription cycle.

There may be multiple ways to express the same pattern using the defined publication, chronology, and enumeration codes.  For instance, the pattern may be expressed enumerating all published issues, or enumerating the omitted issues.  The institution should strive for the most succinct method possible that accurately records the pattern.

The Regularity pattern codes, along with additional examples, are maintained at the Library of Congress and are available online at:  www.loc.gov/marc/chrono_patterns.html.  Questions on coding patterns or establishing new ones should be addressed to the Network Development and MARC Standards Office, Library of Congress, Washington, D.C. 20540-4402 (Email:  ndmso@loc.gov).

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