Is something that was found while researching about PARAM.SFO
There are some official PKG that only have a PARAM.SFO and a LINK.XML inside (and no other folders or files)
Is a bit special type of PKG because doesnt contains an EBOOT.BIN or any executable file
In the LINK.XML you can write an url... and when you try to "boot it" (by clicking in the icon like a normal app/game) what it does is to open the web browser with your link
I was guessing the methods discussed latelly to use javascript inside the link could work
Actually, maybe this can be combined with the other alternatives like modifying webcoreapp.bin or the bookmarks ... dunno at this point it seems there are several ways and is needed to keep open mind
The problem to deal with this special PKG with LINK.XML (but no EBOOT.BIN) is most PKG tools are not going to allow you to make a PKG without EBOOT.BIN
What i was doing at the time i was experimenting with this (with a CFW) was:
1) use a filemanager to copy the custom PARAM.SFO and LINK.XML to dev_hdd0/game/XMLL00001/
2) enter "recovery menu" and "rebuild database"
3) after reboot it appears on XMB like if it was installed normally
In HAN you cant do this though

But there is another way

1) Create the PKG with the custom PARAM.SFO and LINK.XML and a "dummy" EBOOT.BIN (it can be anything)
2) Use the HAN "unlinker" to navigate to the installation path and delete the EBOOT.BIN
3) enter "recovery menu" and "rebuild database" (or just boot it, at the time you boot a content database is updated, but you will have to pass an error at the first boot of the modded PKG)