PubMed

SGML Entity List

This is a list of commonly used SGML entities that NLM can parse. For each entity listed we have provided the hexadecimal UNICODE value, the translation as it will appear in PubMed, and the meaning. Though they are not listed, we do also accept the decimal UNICODE values for the entities listed here; but note that we ONLY accept this subset of UNICODE values. This is not a comprehensive list of accepted characters.

When creating your XML file, please keep in mind the following:

• If it is possible to use an ASCII character to represent an entity, please use the ASCII character. For example, general punctuation such as quotation marks, colons, and number signs may be created with keyboard characters. Note that there are three exceptions to this rule: We require you to use an SGML entity instead of ASCII when creating an ampersand (&) [use &amp;], a less than symbol (<) [use &lt;], and a greater than symbol (>) [use &gt;]

• We prefer that you use SGML entities (first column), but can accept both decimal and hexadecimal UNICODE character references.

 
• If you wish to use a UNICODE value to represent your character, you must place it in the following format: ampersand (&) followed by a pound sign (#) followed by the UNICODE value followed by a semicolon (;). For example, use &#x221F; (hexadecimal value) or &#8735; (decimal value) to represent a right (90 degree) angle.

 
• Use  to indicate superscript, and <inf> </inf> to represent inferior or subscript characters in the <ArticleTitle> and <Abstract> tags.

• Diacritics must be represented with SGML entities even though these diacritics will not appear in the standard PubMed Summary or Abstract displays.  This is required for two reasons: first, a user can view diacritics in the XML display of a PubMed citation if their browser is set to translate the UNICODE/UTF-8 character set and second, many licensees of the MEDLINE database world-wide have the ability to display diacritics and therefore value this coding.

 
• You can test your entities with our PubMed Citation File Validator. In addition to testing the structure of your XML files, it can determine whether the entities you are using are accepted by our parser.

• ISO Latin-1
• ISO Latin-2
• Publishing
• General Technical
• Accented Characters
• Fractions, Super/Subscripts, Punctuation
• Greek Letters
• Monotoniko Greek
• Greek Symbols
• Alternative Greek Symbols
• Relations
• Negated Relations
• Arrows
• Binary Operators
• Added Math Symbols - Operators
• Added Math Symbols - Relations
• Russian Cyrillic
• Non-Russian Cyrillic
• Box and Line Drawing