# When using bibliographystyle plainnat, how do I suppress automatic lettering of misc elements with the same author?

When using the following TeX:

\documentclass[12pt]{article}
\usepackage{natbib}
\usepackage{lipsum}
\usepackage{hyperref}
\bibliographystyle{plainnat}

\begin{filecontents}{test.bib}
@misc{centers2017underlying,
title        = {\textit{Underlying Cause of Death 1999-2017 on CDC WONDER Online Database, released December, 2018. Data are from the Multiple Cause of Death Files, 1999-2017, as compiled from data provided by the 57 vital statistics jurisdictions through the Vital Statistics Cooperative Program}},
author       = {{Centers for Disease Control and Prevention and National Center for Health Statistics}},
howpublished = {\url{https://wonder.cdc.gov/ucd-icd10.html}},
note         = {Accessed: 2019-03-01},
}

@misc{icdcomparabilityratios,
title        = {{A Guide to State Implementation of ICD-10 for Mortality; Part II: Applying Comparability Ratios}},
author       = {{Centers for Disease Control and Prevention and National Center for Health Statistics}},
howpublished = {\url{https://www.cdc.gov/nchs/data/statab/document-for-the-states.pdf}},
note         = {Accessed: 2019-03-01},
}
\end{filecontents}

\begin{document}

\lipsum[1]
\nocite{*}
\bibliography{test}
\end{document}
% Create PDF on Linux: FILE=test; pkill -9 -f ${FILE} &>/dev/null; rm -f${FILE}*aux ${FILE}*bbl${FILE}*bib ${FILE}*blg${FILE}*log ${FILE}*out${FILE}*pdf &>/dev/null; pdflatex -halt-on-error ${FILE}; bibtex${FILE} && pdflatex ${FILE} && pdflatex${FILE} && (xdg-open \${FILE}.pdf &)


Automatic lettering is added after each URL because the authors are the same (highlighted in red):

The automatic lettering may be overridden by specifying year, but I have nothing additional to put there.

Changing to \bibliographystyle{plain} solves the problem, but I need plainnat.

How do I get rid of this automatic lettering?

Edit: As suggested by one answer, adding year with a command that prints nothing still leaves a dangling comma (also used \usepackage[hidelinks]{hyperref} to make it easily visible):

• Note that according to its title page icdcomparabilityratios actually has a year, namely year = {2000},. In this example there is no "a"/"b" any more once you add that year. (Of course the general question remains.) Note that it is in general not best practice to include formatting in the .bib entry: The \textit{...} spanning the entire title of centers2017underlying is something the style should take care of, not you. plainnat knows the url field, so you could say url = {http://....}, instead of howpublished = {\url{http://...}},. – moewe Mar 22 '19 at 6:22
• @moewe Thanks, I do have other cases without years, so as you mention, the general problem remains, but that's a valid point. I need an extra {} to maintain acronym capitalization, but you're right the italics aren't needed. I tried changing howpublished to url but it prefixes the URL with URL which is a bit odd, but I'll consider it. Cheers. – freeradical Mar 22 '19 at 6:33
• I do not recommend to enclose the entire title in curly braces to maintain the capitalisation of acronyms (or proper names) instead you should protect only those words that need protection: title = {Underlying Cause of Death 1999--2017 on {CDC} {WONDER} Online Database, released {December}, 2018. {Data} are from the Multiple Cause of Death Files, 1999--2017, as compiled from data provided by the 57 vital statistics jurisdictions through the Vital Statistics Cooperative Program}, (maybe you see some of the program names as proper names and want to protect those as well) – moewe Mar 22 '19 at 6:44
• Now that I read the title, that gives a strong case to make the year of centers2017underlying read year = {2018}, – moewe Mar 22 '19 at 6:44
• @moewe Good points, thanks! – freeradical Mar 22 '19 at 6:50

One workaround is to add some number of \nothing commands to the end of each otherwise-duplicated author. For example:

\newcommand\nothing{}
@misc{centers2017underlying,
title        = {\textit{Underlying Cause of Death 1999-2017 on CDC WONDER Online Database, released December, 2018. Data are from the Multiple Cause of Death Files, 1999-2017, as compiled from data provided by the 57 vital statistics jurisdictions through the Vital Statistics Cooperative Program}},
author       = {{Centers for Disease Control and Prevention and National Center for Health Statistics}},
howpublished = {\url{https://wonder.cdc.gov/ucd-icd10.html}},
note         = {Accessed: 2019-03-01},
}

@misc{icdcomparabilityratios,
title        = {\textit{A Guide to State Implementation of ICD-10 for Mortality; Part II: Applying Comparability Ratios}},
author       = {{Centers for Disease Control and Prevention and National Center for Health Statistics\nothing}},
howpublished = {\url{https://www.cdc.gov/nchs/data/statab/document-for-the-states.pdf}},
note         = {Accessed: 2019-03-01},
}

• Could you add an example of this workaround to your answer, to clarify how this can be applied? – Marijn Mar 21 '19 at 22:08

Add something that doesn't show up:

\begin{filecontents}{test.bib}
@misc{centers2017underlying,
title        = {\textit{Underlying Cause of Death 1999-2017 on CDC WONDER Online Database, released December, 2018. Data are from the Multiple Cause of Death Files, 1999-2017, as compiled from data provided by the 57 vital statistics jurisdictions through the Vital Statistics Cooperative Program}},
author       = {{Centers for Disease Control and Prevention and National Center for Health Statistics}},
howpublished = {\url{https://wonder.cdc.gov/ucd-icd10.html}},
note         = {Accessed: 2019-03-01\noShow{a}},
}

@misc{icdcomparabilityratios,
title        = {{A Guide to State Implementation of ICD-10 for Mortality; Part II: Applying Comparability Ratios}},
author       = {{Centers for Disease Control and Prevention and National Center for Health Statistics}},
howpublished = {\url{https://www.cdc.gov/nchs/data/statab/document-for-the-states.pdf}},
note         = {Accessed: 2019-03-01\noShow{b}},
}
\end{filecontents}
\documentclass[12pt]{article}
\usepackage{lipsum}
\usepackage{hyperref}
\usepackage{natbib}
\bibliographystyle{plainnat}
\providecommand{\noShow}[1]{}
\begin{document}
\lipsum[1]
\nocite{*}
\bibliography{test}
\end{document}

• I converted your example from @article to @misc, removed the year following the \noShow command (since I don't have a year to specify), and made the authors the same, and I see the same problem with a dangling comma. – freeradical Mar 21 '19 at 20:25
• Did you deleted the generated .bib and .bbl files before recompiling? – Vinccool96 Mar 21 '19 at 20:39
• Yes, I removed those files. There is still a dangling comma after the URL. I edited my question to show a screenshot. – freeradical Mar 21 '19 at 20:47
• Put the \noShow in the note. Also, the noShow parameter souldn't be the same in both. – Vinccool96 Mar 21 '19 at 20:59
• Putting \noshow in the note and removing year did not work - automatic lettering is still added. – freeradical Mar 21 '19 at 21:02