I edited the page N#178898 and the currency and denomination were removed. Later I saw that the select box of currency in the edit page does not have the ECU currency. This also happens in other issuers (Portugal, Sweden…).
The search page does display the ECU currency in the filter. https://en.numista.com/catalogue/index.php?e=espagne&r=&st=all&cat=y&im1=&im2=&ru=&ie=&ca=3&no=&v=&cu=10619&dn=&a=&dg=&i=&b=&m=&f=&t=&t2=&w=&mt=&u=&g=&se=8572&c=&wi=&sw=
This is important because the currencies are removed from the pages when they are edited.

