The Abstract (AB) field contains a description of the content of the document or article and is a summary of its contents. You can search for any word in this field.

The Authors (AU) field contains the authors of the article. The format for authors is last name followed by one or more initials: Smith JC or Smith J. Enter the last name, or if it is a common name, enter the last name and first initial. If you are unsure of the spelling of the last name (macdonald or mcdonald), enter one version and then scroll through the list of names to find the other.

Misspelled and corrected names are also included in the Authors Index to ensure all possible matches. Only correct author names display, while incorrectly spelled names are indexed along with the correct spelling of the name.

The Comments (CM) field contains an indication that the article either contains a comment on another article or is commented on in another article. The CM field begins with the indication "Comment On" or "Comment In" and then displays the Journal Abbreviation (JA), Date of Publication (DP), the Volume (VO), Issue/Part (IP), and Page (PG).

Articles that contain a comment display with [comment] appended to the end of the article title. Articles that are commented on in another article display with [see comment] appended to the end of the article title.

The MeSH Subject Headings (DE) field contains the Medical Subject Headings used by indexers at the National Library of Medicine (NLM) to describe the content of an article.
MeSH headings are entered into the index as phrases and should be searched as they appear in the NLM MeSH books.

The DOI (DO) field contains the Digital Object Identifier - a unique and persistent digital identification code for any object of intellectual property.

The DOI itself consists of two parts: a prefix which is assigned to each publisher by the administrative DOI agency, such as "10.1097," and a suffix which is assigned by the publisher and can be any code that the publisher chooses, such as "00045415-200111000-00002." The full DOI appears as such: "10.1097/00045415-200111000-00002".

Search all DOI's replacing punctuation with spaces such as "10 1016 j adnc 2003 08 001".do. for the displayed DOI of 10.1016/j.adnc.2003.08.001.

The Subject Heading Word (DW) index allows you to retrieve every MeSH subject heading and Publication Type that include a particular word. Do this by searching nbsp;a single word in the Subject Heading Word (DW) field.

The Electronic Date of Publication (EP) is the date the record was sent to NLM. This index appears in the format YYYYMMDD.

The ISSN Electronic (ES) field contains the Electronic International Standard Serial Number (EISSN) for the journal in which an article was published. It appears as an 8 digit number, separated by a hyphen: 0028-4793. To retrieve all of the articles for a journal, search by the Journal Name (JN).

Both Electronic and Print ISSNs can be searched in the ISSN (IS) field.

The Authors Full Name (FA) field contains the full name of the authors of the article when available.

Subheadings are qualifiers added to MeSH subject headings to refine their meaning.  Terms such as "etiology" or "therapy," when combined with a MeSH heading, give a precise idea of what an article covers.

The Floating Subheadings (FS) field contains both the 2-letter codes, such as "po," and the full heading, such as "poisoning." These are displayed following the corresponding MeSH Subject Headings.

The Subject Heading Word (HW) index allows you to retrieve every Ovid Descriptor that includes a particular word. Do this by searching a single word in the Subject Heading Word (HW) field.

The Investigator Affiliation (IA) field contains the affiliation of the investigator of the article, and displays as part of the Institution (IN) field.

The ISSN Linking (IL) index contains an identifier intended to provide a mechanism to group the various medium versions of a continuing resource. The purpose of the ISSN-L is to provide a mechanism for grouping, or collocating, the various medium versions of a resource, for instance, the print and online versions of a journal per ISO 3297 standards.

"The first ISSN assigned, in the ISSN Register, to any medium version of a continuing resource shall be designated by default to function also as the ISSN-L and shall apply to all other media versions of that resource identified in the ISSN Register.

The ISSN Linking field will be used only for new records added during the 2008 production year (although NLM still does not know the timing when all will be in place to start to appear on records).

The Institution (IN) field contains the primary author's affiliation, which is usually the source for a reprint of the article. This index also contains the investigators affiliation. This information can be searched in most documents since 1988, but records from earlier years which were added to the database after 1988 may also contain institution information. Beginning with documents indexed in 1996, the primary author's email address will also be included, if present in the journal.

The information is taken from the source document and is not standardized. Enter the single most descriptive word in an institution (harvard, not university). Consider both full spellings and abbreviations.

The Investigator (IR) field contains personal names of individuals (e.g., collaborators and investigators) who are not authors of a paper but rather are listed in the paper as members of a collective/corporate group that is an author of the paper.

The format for authors is last name followed by one or more initials:  Smith JC or Smith J.

The ISSN Print (IS) field contains the International Standard Serial Number (ISSN) for the journal in which an article was published. It appears as an 8 digit number, separated by a hyphen: 0028-4793. To retrieve all of the articles for a journal, search by the Journal Name (JN).

Both Electronic and Print ISSNs can be searched in the IS index.

The Journal Name (JN) field contains the full name of the journal in which the article was published. Journal names are indexed as phrases, so enter enough letters of the journal name to locate the name in the index, as in new engl (for New England Journal of Medicine).This field displays as part of the Source (SO) field.

If the first word of a Journal Name is “The”, it has been removed.

The Locally Held (LH) field indicates (with a "Y" or an "N") if a journal is held locally.

The Local Messages (LM) field contains messages created by the System Administrator to indicate information about journals held in your local library system.

The Name of Substance Word (NM) index contains single words from the CAS Registry/EC Number/Name (RN) field and is used to search portions of chemical names. This field displays as part of the CAS Registry/EC Number/Name (RN) field.

The Name of Substance Word (NM) field data starts in 1980.

The General Note (NT) field contains general supplementary information about an item. The notes may include information on the availability of a bibliography, ordering information for dissertations or hearings, or general summaries of materials such as manuals or scripts. A series title may appear for a book or for audiovisual materials.

The Other Abstract (OA) field includes a brief abstract written by collaborating partners. The OA field is indexed in Abstract (AB) field, and contains all searchable words from the other abstract. Collaborating partners include:

The Primary Author (PA) field contains the first author listed for the article.  This allows users to search for articles by any primary author. Author names display in Authors (AU) and Authors Full Name (FA) fields.

Searching for smith rh.pa. will return results where Smith RH was listed as the main author of the article.

The Page (PG) field consists of the inclusive pagination of a journal article. Often a journal title combined with the beginning page number is enough to locate a citation. You can search for pages with alphanumeric characters, such as "a1.pg."

This field displays as part of the Source (SO) field.

The Personal Name As Subject (PN) field displays the name of a well-known person if they are discussed in an article, such as an interview or obituary.

The format for Personal Name is the same as for Author -- last name and initials: Bach JS. Enter a last name and one initial if known.

In addition to indexing documents with Medical Subject Headings, the indexers at the National Library of Medicine assign terms to describe the article type. Publication Types include such classifications as reviews, clinical trials, directories and letters. These terms appear in the Publication Type (PT) field.

To view the index, enter enough letters to distinguish a publication type (jour for "journal article"); the entire index is quickly scrollable to determine all possible publication types.

With the 2005 reload, Publication Types are also loaded into the MeSH. Because some Publication Types are also MeSH terms, the syntax to enter the Tree is "Randomized controlled trial [publication type]". To post the results from the Tree without entering the Tree, the syntax is: "Randomized controlled trial [publication type]"/ or Randomized controlled trial.pt.

The CAS Registry/EC Number/Name of Substance (RN) field contains the Chemical Abstracts Service Registry number or Enzyme Commission number for a compound mentioned in an article. If the generic compound name can be determined, it is included. The RN field was added to Ovid MEDLINE in 1980. 

Registry numbers appear with hyphens (50-00-0). Search for EC numbers in the format ec 1 1 1 1 adh1c protein human. Chemical names appear with all special characters except hyphens removed.

The Record Owner (RO) field contains the owner of the record.

The Secondary Source AN (SA) index contains the unique identifiers of outside resources discussed in MEDLINE articles. The display includes the Secondary Source ID (SI) and the unique identifier seperated by a forward slash, for example: RefSeq/NM_020533.

If you prefer to search all works from a particular databank use the Secondary Source ID (SI) field.

The Journal Subset (SB) field identifies the subset for MEDLINE records from certain journal lists or records on specialized topics. Some of these values are found on extremely small numbers of records. Citations may contain more than one occurrence of this field. The value is true at the time the record was created. If the status of a journal changes, the value on the record does not change.

Subset field values and their definitions are as follows. Note that several are closed subsets no longer being assigned.

The Ovid Descriptor (SH) field contains the Ovid Descriptor that is assigned to the record to describe the content and is based on the Nursing Subject Thesuarus. These are largely based on NLM's MeSH and other sources such as Library of Congress.

The Secondary Source ID (SI) identifies secondary source databanks with unique identifiers of outside resources discussed in MEDLINE articles. The field is composed of the source acronym:   GENBANK

The Secondary Source ID (SI) formerly known as the Molecular Sequence (MS) field was added to Ovid MEDLINE (R) in 1988.

The Secondary Source Linking (SL) index contains the URL to the outside resources discussed in MEDLINE articles when the Secondary Source ID is either ClinicalTrials.gov or ISRCTN. The index contains the the URL, for searching ease use the Secondary Source AN (SA) index: nct00000150.sa..

The Source (SO) field includes a display of all the basic information needed to locate a citation, including the full Journal Name (JN) or Monograph Publisher (PB), issue/Part (IP) , Page (PG) and Date of Publication (DP)

The Status (ST) field contains the status of the citation, and contain one of the following:

The Title (TI) field contains the English language version of a title. For documents which were not written in English, the original or transliterated title appears in a separate field, Original Title (OT).

The title sometimes includes notes, in brackets, about the article, such as an indication that it is a letter, editorial, or comment.

The Text Word (TW) field is an alias for all of the fields in a database which contain text words and which are appropriate for a subject search.

The Text Word field in OVRN includes Title (TI) and Abstract (AB).

The Unique Identifier (UI) field contains a number which uniquely identifies each document in the database. When searching this field, include all leading zeros and internal hyphens.

The Update Date (UP) field contains the date the record was added to Ovid Nursing (R) since reload completion.  The Update Date for existing records changes with each global reload to reflect the date Ovid starts processing the reload data. The UP field appears in the format YYYYMMDD.

The Catalog Holdings (XH) field indicates (with a "Y" or an "N") if a journal is held locally.

Ovid Nursing Databse is comprised of data from the National Library of Medicine's (NLM) MEDLINE and other Ovid database journals of which the copyrights for the journal articles are held by their respective publishers. NLM represents that the data provided is formulated with a reasonable standard of care. Except for this representation, and as otherwise specifically provided herein, NLM makes no representations or warranties, expressed or implied. This includes but is not limited to, any implied warranty of merchantability or fitness for a particular purpose, with respect to the NLM databases, and NLM specifically disclaims any such warranties and representations. Downloading data is permitted for personal use only. Some material in the NLM databases is from copyrighted publications of the respective copyright claimants. Users of the NLM databases are solely responsible for compliance with any copyright restrictions and are referred to the publication data appearing in the bibliographic citations, as well as to the copyright notices appearing in the original publications, all of which are hereby incorporated by reference.

The following use of data from article with a Record Owner of NLM requires no written permission from or signed license agreement with NLM.

Users may download small amounts of data, e.g., the bibliographic citation and MeSH® terms, for a small number of NLM citations for redistribution either via a printed publication or in electronic form using the Internet, World Wide Web, etc. Downloading from a MEDLARS licensee, such as OVID is subject to the licensee's approval.

Definitions:

1. Download includes ftping results of an online search, arranging for the results of an automatic stored search to be available for ftp, ftping MEDLARS data from the NLM server (nlmpubs.nlm.nih.gov), or a traditional download using a modem.
2. Small is defined as approximately 1,000 records per month from MEDLINE; 12,000 per year. Retrospective pulls of MEDLINE may include up to approximately 12,000 records for each year covered. For other MEDLARS databases, fewer than 25% of records in the file may be downloaded. For larger portions of a MEDLARS database, contact Janer@nlm.nih.gov or 301-496-7706 for licensing information.
3. Data is defined as bibliographic citations and MeSH terms. This document grants permission to download only the bibliographic citations and MeSH terms, it does not cover author abstracts from the journals which are included in MEDLINE and other MEDLARS databases. Users should obtain an opinion from their legal counsel for any use they plan for the author-generated abstracts in the MEDLARS database.

Terms and Conditions:

Users must ensure that all downloaded publicly accessible data stored in electronic form for over one year must be in compliance with the following provisions of the NLM license agreement:

1. Users of this data must be provided a clear description of how the product/service was derived, indicating the currency and the source database.
2. At least annually, the data downloaded must be corrected to incorporate the corrections NLM has mad