<p>We have <a href="https://stats.stackexchange.com/questions/tagged/augmented-dickey-fuller" class="post-tag" title="show questions tagged &#39;augmented-dickey-fuller&#39;" rel="tag">augmented-dickey-fuller</a> tag with 148 questions. </p>

<p>There are <a href="https://stats.stackexchange.com/search?q=ADF">407 questions</a> I find when searching for ADF (Augmented Dickey Fuller).</p>

<p>There are <a href="https://stats.stackexchange.com/search?q=kpss">174 questions</a> I find when searching for KPSS (Kwiatkowski-Phillips-Schmidt-Shin).</p>

<p>Both the ADF Test as well as the KPSS test are tests which test whether a time series is stationary.  The Null hypothesis of the ADF test is that there is a Unit root. The Null hypothesis of the KPSS Tests is that the time series is stationary. </p>

<p>As KPSS test more or less the complement to the ADF test I propose to create a tag for the KPSS test as well. </p>

<p>More generally we could discuss the same issue for other tests, e.g. the Phillips-Perron Test.</p>
