Ad-hoc templates are used for one page only, for which they were created - this is why they are not offered in the template selection for another page.
In other words, ad-hoc templates are not re-usable (the ad-hoc template is also deleted when the page is deleted).
You need to save the ad-hoc template as a new one. What you already did.
原文：http://www.cnblogs.com/chucklu/p/7891038.html