OK, here is what I have found to work:
"pear search DHTMLRules" produces the following:
Retrieving data...0%
Matched packages, channel pear.php.net:
=======================================
Package Stable/(Latest) Local
HTML_QuickForm_DHTMLRulesTableless 0.3.3 (beta) DHTML replacement for the standard JavaScript alert window for client-side
validation using the tableless renderer
Then, "pear install HTML_QuickForm_DHTMLRulesTableless" gets me the following hint:
Failed to download pear/HTML_QuickForm_DHTMLRulesTableless within preferred state "stable", latest release is version 0.3.3, stability "beta", use "channel://pear.php.net/HTML_QuickForm_DHTMLRulesTableless-0.3.3" to install
install failed
Still following the bread crumps listed above, I tried "pear install channel://pear.php.net/HTML_QuickForm_DHTMLRulesTableless-0.3.3" and found:
Failed to download pear/HTML_QuickForm_Renderer_Tableless within preferred state "stable", latest release is version 0.6.2, stability "beta", use "channel://pear.php.net/HTML_QuickForm_Renderer_Tableless-0.6.2" to install
WARNING: "pear/HTML_QuickForm_Controller" is deprecated in favor of "pear/HTML_QuickForm2"
Did not download optional dependencies: pear/HTML_QuickForm_Controller, use --alldeps to download automatically
pear/HTML_QuickForm_DHTMLRulesTableless requires package "pear/HTML_QuickForm_Renderer_Tableless" (version >= 0.4.0)
pear/HTML_QuickForm_DHTMLRulesTableless can optionally use package "pear/HTML_QuickForm_Controller" (version >= 1.0.7)
No valid packages found
install failed
The successful sequence of Pear install commands is:
"pear install channel://pear.php.net/HTML_QuickForm_Renderer_Tableless-0.6.2" with these results:
WARNING: "pear/HTML_QuickForm" is deprecated in favor of "pear/HTML_QuickForm2"
downloading HTML_QuickForm_Renderer_Tableless-0.6.2.tgz ...
Starting to download HTML_QuickForm_Renderer_Tableless-0.6.2.tgz (7,054 bytes)
.....done: 7,054 bytes
install ok: channel://pear.php.net/HTML_QuickForm_Renderer_Tableless-0.6.2
then
"pear install channel://pear.php.net/HTML_QuickForm_DHTMLRulesTableless-0.3.3" got me the following:
WARNING: "pear/HTML_QuickForm_Controller" is deprecated in favor of "pear/HTML_QuickForm2"
Did not download optional dependencies: pear/HTML_QuickForm_Controller, use --alldeps to download automatically
pear/HTML_QuickForm_DHTMLRulesTableless can optionally use package "pear/HTML_QuickForm_Controller" (version >= 1.0.7)
downloading HTML_QuickForm_DHTMLRulesTableless-0.3.3.tgz ...
Starting to download HTML_QuickForm_DHTMLRulesTableless-0.3.3.tgz (6,396 bytes)
.....done: 6,396 bytes
install ok: channel://pear.php.net/HTML_QuickForm_DHTMLRulesTableless-0.3.3