$generichide is like $elemhide except that it disables only generic hiding rules, meaning hiding rules with no domain specifiers, or "with a few exceptions" (I might need to look into the code to see what is meant by "a few" but for now it looks like "a few" means "fewer than 1").
$genericblock is like $document except that it disables only generic blocking rules, meaning blocking rules with no $domain or $sitekey option, or "with a few exceptions" (in the same sense as above) in the $domain option.
The purpose of these experimental options is to whitelist the common generic rules that anti-adblock technology tests against, without painstakingly doing so on a script-by-script basis or outright allowing all content on a page.
These should at least be mentioned in the Wiki, in case users of this abandoned extension wonder why they don't work; both options exist only for whitelist rules: https://adblockplus.org/development-builds/new-filter-options-generichide-and-genericblock
$generichideis like$elemhideexcept that it disables only generic hiding rules, meaning hiding rules with no domain specifiers, or "with a few exceptions" (I might need to look into the code to see what is meant by "a few" but for now it looks like "a few" means "fewer than 1").$genericblockis like$documentexcept that it disables only generic blocking rules, meaning blocking rules with no$domainor$sitekeyoption, or "with a few exceptions" (in the same sense as above) in the$domainoption.The purpose of these experimental options is to whitelist the common generic rules that anti-adblock technology tests against, without painstakingly doing so on a script-by-script basis or outright allowing all content on a page.