The "verified" tag often refers to versions that include a "hash check" or safety verification. This ensures the file isn't corrupted before the console attempts to write it to the NAND (internal flash memory).
Proper folder structure is vital. If files are in the wrong place, the Wii will not detect them. Set up your storage device as follows:
The phrase "WAD Manager 18 verified" is not a standard version number. Based on community discussions, it refers to that has been verified to work with cIOSX rev18 .
Standard Wii homebrew applications only require a .dol or .elf file, along with an icon.png and meta.xml , inside an apps folder on your SD card.
If you want to ensure your system is fully protected before experimenting with homebrew files, tell me: Do you currently have or BootMii installed? What system menu version is your Wii running? Are you trying to install a game or a system channel ?