Cfrgtkky

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):

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

newcommandnothing{}

@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 Statisticsnothing}},

  howpublished = {url{https://www.cdc.gov/nchs/data/statab/document-for-the-states.pdf}},

  note         = {Accessed: 2019-03-01},

}

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: 2019-03-01noShow{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: 2019-03-01noShow{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}