After observing the many ways we do use icons for applications in Nemo I though to write a proposal and recommendation on two ways of doing things, because I do not see more than two ways that would make sense.
[Desktop Entry] Name=Terminal Icon=icons-Applications-terminal
This is a named icon. Named icon comes from the theme and can have any supported suffix like png, jpg or svg. Icons are in the
icons directory in the theme - not the other directories like images or svg.
/usr/share/themes/base/meegotouch/iconsand refer to them by as named icons.
If icon exists in base theme, it is available no matter what theme is used. It can be themed by new themes if needed, its size and meaning can be modified by theme designers. Overall - this is easy way to make the icon of your app to fit.
[Desktop Entry] Name=Bunny Racer Pro Icon=/usr/share/icons/hicolor/80x80/bunny-racer.png
By giving a path to the icon things are made easy and clear. There is never a confusion over who owns an icon and who provides it. The application in question does. The icon is given and will not be themed or changed by anyone, ever. The location on the filesystem can be anywhere, few suitable places come to mind:
* /usr/share/icons/hicolor/80x80 * /usr/share/icons/hicolor/64x64 * /usr/share/pixmaps
[Desktop Entry] Name=Terminal Icon=/usr/share/themes/base/meegotouch/svg/icons-Applications-terminal.svg
[Desktop Entry] Name=Marble Icon=/usr/share/themes/n900de/meegotouch/icons/icons-Applications-marble.svg