Suggestion: annotate liquid-layout.css to flag up non-obvious behaviour of sidebar classes.

Not really a "feature request", more of a "feature suggestion".

I was just making an alternative page.tpl.php without sidebars (to try how that'd look on a small screen device). It wasn't working at first: the space for the sidebar was appearing even though the content wasn't. Eventually I discovered this useful article:
http://www.lullabot.com/articles/drupal-performance-tip-block-visibility
which explained why it was happening.

Now I've annotated my layout-liquid.css file to remind me of this, as follows:

/* (If there are any blocks allocated to the sidebars, then the sidebar class tags will be included by core, even if the sidebar regions don't appear in page.tpl.php. See http://www.lullabot.com/articles/drupal-performance-tip-block-visibility ) */

I've stuck that in below the three entries that finish up

.two-sidebars #content .section {
  padding-left: 180px; /* The width + left margin of .region-sidebar-first. */
  padding-right: 190px; /* The width + right margin of .region-sidebar-second. */
}

Anyway, so I thought I'd make the suggestion of including some such warning (maybe smaller if it can be boiled down) in Zen's own liquid-layout.css.

I realise it's always debatable how much documentation to include (not to rewrite the manual in comments :-) ), so not at all assuming you'll actually want to... just thought this was sufficiently non-obvious behaviour as to be a possible candidate.