Skip to main content
U.S. flag

An official website of the United States government

Here’s how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

This is a preview of updates coming to the Technical Bulletin's website in April 2026. Return to current site.
Read more about the modernization release schedule in this announcement.
Comment via the yellow feedback button in the lower right hand corner of the page. Contact the NLM Help Desk with any questions or concerns.

This is archived content.

Links may have become inactive over time. Visit Archive-It   to find the original published layout.

Formulas to Display in PubMed Titles and Abstracts

Formulas to Display in PubMed Titles and Abstracts. NLM Tech Bull. 2018 Mar-Apr;(421):e1.

March 07, 2018 [posted]
June 06, 2018 [Editor's note added]

[Editor's note: This change was implemented in PubMed on June 6, 2018.]

On June 1, 2018, the National Library of Medicine will begin displaying formulas in citation titles, abstracts, and keywords in PubMed. Currently, formulas are replaced with [Formula: see text] (see Figure 1).


formula: see text replacement in the PubMed abstract display.
Figure 1: Formula replaced with [Formula: see text] in the PubMed abstract display.

With this enhancement to PubMed, you will see formulas in the PubMed summary and abstract displays when these data are available in new citations (see Figure 2).


formula in the PubMed abstract display.
Figure 2: Formula shown in the PubMed abstract display after June 1, 2018.

Also, we will be including the MathML 3.0 element tags in PubMed XML. To support the addition of MathML tagging in our XML, we have created a new, forthcoming DTD that will be in use as of June 1, 2018. You can download the forthcoming DTD for June 2018 now. Existing content will be valid against the new DTD. You can also download sample XML files with MathML 3.0 tags.