I have several picture directories:
pics [this one]
cpics cartoons (public)
cpics2 cartoons (protected)
dpics Diagrams
spics Students (protected)
	(could edit protection to let the students seem themselves/each other.)
privpics private photos (protected)
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I use picindex3.php to layout most of these.

picindex4.php is apparently dangerous for hackers.  Its file links are:
/home/steve/public_html/php/picindex4.php
/home/steve/public_html/spics/panel/index.php
/home/steve/public_html/spics/adv/index.php

/home/steve/public_html/php/picindex4.php
/home/steve/dropbox/docs/DOCsPHP/picindex4.php
/home/steve/public_html/spics/panel/index.php
/home/steve/public_html/spics/pospsy/index.php
/home/steve/public_html/spics/adv/index.php
/home/steve/public_html/pics/qpics/index.php
/home/steve/public_html/dropbox/docs/DOCsPHP/picindex4.php
/home/steve/MAC/unixdropbox/docs/DOCsPHP/picindex4.php
/home/steve/recover_html/public_html/dropbox/docs/DOCsPHP/picindex4.php
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For private or copyright pics, put them in a protected dir e.g. privpics.

Image files e.g. .jpg will be displayed as IMGs.

x.html will be clickable links (potentially to an img file somewhere).

x.img will be assumed to contain a URL to an img, displayed as local files;
	although if destination is protected, then will appear as a broken IMG
	So if not there or protected, broken thumbnail; if ok then both
	thumbnail and on clicking the whole thing.