Unique counter for all foot, side and end notes

Question

When used together, as in the MWE, the text might be plagued of identical numbered marks, that is rather confusing.

I want to have marks in this MWE ordered from 1 to 9 instead of three indistinguishable series from 1 to 3.

More clever solutions (using marks of different colors, mixing arabic and roman numbers with alphabetic marks, other that you can imagine ...) are also welcome.

\documentclass{article}
\usepackage{sidenotes}
\usepackage{endnotes}

\begin{document}

See the sidenote\sidenote{A side note} and the footnote \footnote{A foot note}. 
See the sidenote\sidenote{A side note} and the footnote \footnote{A foot note}. 
See the endnote\endnote{An end note}. See the endnote\endnote{An end note}. 
See the note\sidenote{A side note} (of what type?) and the 
note\footnote{A foot note}(what type?) and the note\endnote{An end note} 
(where?).

\theendnotes

\end{document}

Answer 1

I'm not so sure it's wise to have three different kinds of notes. This seems to be predestined to confuse readers. Having them all numbered with the same counter seems even more confusing to me: why is number 1 in the margin, number 2 in the footer and number 3 at the end of the section? Is there some pattern to it?

If really all three note types are required the simplest thing to me seems to use different kinds of counter formats:

\documentclass{article}
% use symbols for footnotes:
\usepackage[symbol]{footmisc}

\usepackage{sidenotes}    
% change the sidenote counter format:
\renewcommand*\thesidenote{\alph{sidenote}}

\usepackage{endnotes}

\begin{document}

See the sidenote\sidenote{A side note} and the footnote \footnote{A foot note}.
See the sidenote\sidenote{A side note} and the footnote \footnote{A foot note}.
See the endnote\endnote{An end note}. See the endnote\endnote{An end note}. See
the note\sidenote{A side note} (of what type?) and the note\footnote{A foot note}%
(what type?) and the note\endnote{An end note} (where?).

\theendnotes

\end{document}