"Pretty Home Page" is not found in official PHP history. But I saw several people call PHP that way on the internet, and even in some books, teaching & publications:
Php5: The Pretty Home Page Scripting Language
ACID useds PHP (Pretty Home Page) scripting language,
components such as Apache, Pretty Home Page (PHP),
Originally Pretty Home Page Tools
Introduzione a PHP (at PHP Day 2003):
Storia del PHP : Rasmus Lerdorf e «Pretty Home Page»
PHP : "Pretty Home Page" inventé par Rasmus Lerdorf en 1994
20 years Pretty Home Pages
Although Pretty Home Page is another criminal hack of the unix lineage,
Besser PHP programmieren (in a comment on Amazon):
PHP, das stand einmal für "Pretty Home Page" und dieser Name suggerierte irgendwie etwas hobbymäßiges. Später wurde dies in "PHP Hypertext Processor" umgewidmet und sollte andeuten, dass sich die Sprache professionalisiere.
(Translation: PHP, that once stood for "Pretty Home Page" and this name somehow suggested something hobby-like. Later, this was repurposed to "PHP Hypertext Processor" and was intended to indicate that the language was professionalizing.)
It's a legacy from the times when PHP were just a "Pretty home page" form interpreter and strongly discouraged nowadays.
Was "Pretty Home Page" just a funny nickname of PHP? Or was it once PHP's real name?
Someone has already asked this question in another forum, but received no conclusive answers: OFF-TOPIC Original PHP acronym