microtype Tracking warning

Question

To save space in tables, I want to reduce the tracking in the words. To do this I am using code from here.

The code below works correctly and is displayed as expected, but for every occurence of \test I am getting a warning like this: Package microtype Warning: tracking amount list `output.tex/8' will override list `default' for font `OT1////' on input line 8. I wasn't able to figure out why this happens, maybe someone with deeper insight could help me out here.

\documentclass{article}
\usepackage{microtype}

\newcommand\narrowstyle{\SetTracking{encoding=*}{-50}\lsstyle}
\newcommand{\test}{\narrowstyle Test}
\begin{document}
\test\test\test
\end{document}

Answer 1

If you're absolutely sure that the warning messages are innocuous, you could load the microtype package with the option verbose=silent.

Incidentally, I would replace

\newcommand{\test}{\narrowstyle Test}

with

\newcommand{\test}{{\narrowstyle Test}}

in order to limit the scope of \narrowstyle.

For more on this option, see section 3.5, entitled "Miscellaneous options" of the user guide of the microtype package.

\documentclass{article}
\usepackage[verbose=silent]{microtype}
\newcommand\narrowstyle{\SetTracking{encoding=*}{-50}\lsstyle}
\newcommand{\test}{{\narrowstyle Test}}

\begin{document}
\test\test\test --- looks dreadful

TestTestTest --- default
\end{document}

Answer 2

I ended up using \textls instead, which works fine and without errors and doesn't require silencing any errors (though that is also a helpful option):

\documentclass{article}
\usepackage{microtype}
\newcommand\narrowstyle[1]{\textls[-50]{#1}}
\newcommand{\test}{\narrowstyle{Test}}

\begin{document}
\test\test\test
\end{document}

Note that if you wanted to keep the original semantics, @Roberts answer is probably the best option:

\SetTracking[context=narrow]{encoding=*}{-50}
\newcommand\narrowstyle{\microtypecontext{tracking=narrow}}