<h3 dir="auto">The wording in the update docs is (emphasis added):</h3>
<p dir="auto">In a future version of pandas <code class="notranslate">pandas.concat()</code> will no longer sort the non-concatenation axis when it is not already aligned. (...)</p>
<p dir="auto">To keep the previous behavior (sorting) and silence the warning, pass <code class="notranslate">sort=True</code>.<br>
<strong>To accept the future behavior (no sorting), pass <code class="notranslate">sort=False</code></strong></p>
<p dir="auto"><a href="https://pandas-docs.github.io/pandas-docs-travis/whatsnew.html#concatenation-will-no-longer-sort" rel="nofollow">https://pandas-docs.github.io/pandas-docs-travis/whatsnew.html#concatenation-will-no-longer-sort</a></p>
<h3 dir="auto">But the wording in the <code class="notranslate">FutureWarning</code> messages is (emphasis added):</h3>
<p dir="auto">Sorting because non-concatenation axis is not aligned. A future version<br>
of pandas will change to not sort by default.</p>
<p dir="auto"><strong>To accept the future behavior, pass <code class="notranslate">sort=True</code>.</strong><br>
To retain the current behavior and silence the warning, pass <code class="notranslate">sort=False</code></p>
<p dir="auto"><a href="https://github.com/pandas-dev/pandas/blob/c4da79b5b322c73d8e61d1cb98ac4ab1e2438b40/pandas/core/indexes/api.py">https://github.com/pandas-dev/pandas/blob/c4da79b5b322c73d8e61d1cb98ac4ab1e2438b40/pandas/core/indexes/api.py</a></p>
<p dir="auto">It needs to be clearer that current default is still <code class="notranslate">sort=True</code> but will revert to <code class="notranslate">sort=False</code> in a future version.</p>
<h4 dir="auto">Problem description</h4>
<p dir="auto">Pandas 0.23.0 adds a new warning when calling <code class="notranslate">concat</code> with misaligned axes (<a class="issue-link js-issue-link" data-error-text="Failed to load title" data-id="311461033" data-permission-text="Title is private" data-url="https://github.com/pandas-dev/pandas/issues/20613" data-hovercard-type="pull_request" data-hovercard-url="/pandas-dev/pandas/pull/20613/hovercard" href="https://github.com/pandas-dev/pandas/pull/20613">#20613</a>):</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="FutureWarning: Sorting because non-concatenation axis is not aligned. A future version
of pandas will change to not sort by default.

To accept the future behavior, pass 'sort=True'.

To retain the current behavior and silence the warning, pass sort=False"><pre class="notranslate"><code class="notranslate">FutureWarning: Sorting because non-concatenation axis is not aligned. A future version
of pandas will change to not sort by default.

To accept the future behavior, pass 'sort=True'.

To retain the current behavior and silence the warning, pass sort=False
</code></pre></div>
<p dir="auto">This seems strange; I'd assume that <code class="notranslate">sort=True</code> would give the current behaviour, and <code class="notranslate">sort=False</code> the future behaviour, as in the docs for <code class="notranslate">concat</code>:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="Explicitly pass sort=True to silence the warning and sort. Explicitly pass
sort=False to silence the warning and not sort."><pre class="notranslate"><code class="notranslate">Explicitly pass sort=True to silence the warning and sort. Explicitly pass
sort=False to silence the warning and not sort.
</code></pre></div>
<p dir="auto">I'm assuming the docs are right and the warning is wrong?</p>