Sorting bibliography with bibulous with authors and institutions

Question

After reading several posts in this forum I chose bibulous to create my own bibliography style. I'm already quite happy with the solution in this example here. However, I need to sort the references not only after author year, as in the example above, but because I sometimes don't have an author also after institutions. So I need it to be sorted first alphabetically and then after the year, whereas the author and the institution should be on the same level.

As said above I like this approach quite a lot so I use it as a MWE. I only removed the author in one bib entry so it's easier to test whether it works or not.

Thank you very much for your help in advance!

\documentclass[11pt, a4papter] {scrartcl}
\usepackage{natbib}

\usepackage{filecontents}
\begin{filecontents*}{svenz.bst}
TEMPLATES:
book =  [<au>.] [\textit{\enquote{<title>}}.] [<address> <year>.]
electronic = [<au>.] [\textit{<institution>.}] [<date>.] [\enquote{<title>}.] [<url>.] [<dateofchange>.] [<urldate>.]
oral = [<au>.] [<interviewer>,] [<date>,] [<address>.]
inbook = [<au>.] [\enquote{<title>}.] [In: <booktitle>,] hg. v. [<publisher>.] [<address>] [<place>.] [<pages>.]
article = [<au>.] [\enquote{<title>}.] [\textit{<journal>,] [<year>,] [<number>,}] [<pages>.]

SPECIAL-TEMPLATES:
citelabel = <authorlist.0.last>, <year>
sortkey = <authorlist.0.last><year>

OPTIONS:
namelist_format = last_name_first
use_firstname_initials = False
\end{filecontents*}
\begin{filecontents}{\jobname.bib}
@Electronic{gehalt,
  author      = {Rütti, Nicole},
  institution = {NZZ Online},
  year        = {2017},
  date        = {2017-07-27},
  title       = {Sind Frauen wirklich selber schuld am tieferen Gehalt?},
  url         = {https://www.nzz.ch/wirtschaft/frauen-und-lohnverhandlungen-auf-stoeckelschuhen-rueckwaerts-ueber-ein-minenfeld-laufen-ld.1307984},
  urldate     = {2018-10-14},
}


@Electronic{ackeret,
  author      = {Ackeret, Markus},
  institution = {NZZ Online},
  year        = {2017},
  date        = {2017-05-25},
  title       = {Im Übereifer des politischen Gefechts},
  url         = {https://www.nzz.ch/international/debatte-um-die-bundeswehr-im-uebereifer-des-politischen-gefechts-ld.1296154},
  urldate     = {2018-10-14},
}

@Electronic{Lenz1,
  institution = {Tages-Anzeiger Online},
  year        = {2017},
  date        = {2017-07-04},
  title       = {Rechenspiele der Armee haben politische Folgen},
  url         = {https://www.tagesanzeiger.ch/schweiz/standard/rechenspiele-der-armee-haben-politische-folgen/story/19945957},
  urldate     = {2018-10-16},
}
\end{filecontents}

\begin{document}
Lorem ipsum dolor sit amet, \citet{gehalt} consetetur sadipscing elitr, 
\cite{Lenz1}. Lorem ipsum dolor sit amet. \cite{ackeret}

\bibliographystyle{svenz}
\bibliography{\jobname}
\end{document}

So in the end it should look like:
Ackeret, Markus. [. . .]
Rütti, Nicole. [. . .]
Tages-Anzeiger Online. [. . .]

Answer 1

The usual approach for cases like this (which also works for BibTeX and biblatex) would be to give Tages-Anzeiger Online as author, i.e.

@Electronic{Lenz1,
  author      = {{Tages-Anzeiger Online}},
  year        = {2017},
  date        = {2017-07-04},
  title       = {Rechenspiele der Armee haben politische Folgen},
  url         = {https://www.tagesanzeiger.ch/schweiz/standard/rechenspiele-der-armee-haben-politische-folgen/story/19945957},
  urldate     = {2018-10-16},
}

(the double braces are needed to avoid parsing the name as consisting of first and last names, see Using a 'corporate author' in the "author" field of a bibliographic entry (spelling out the name in full)). In the comments you mention that you don't like that because the Tages-Anzeiger Online should be in italics.

In that case I suggest you change the sortkey in SPECIAL-TEMPLATES:. Since the citations were also not displaying nicely with missing authors, you should probably change citelabel as well.

SPECIAL-TEMPLATES:
citelabel = [<authorlist.0.last>|<editorlist.0.last>|<institution>](<year>)
sortkey   = [<authorlist.0.last>|<editorlist.0.last>|<institution>]<year>

With that code in the .bst file I get