xr4v3nx, code $LAST_NEWS$ is responsible for showing the last news from the site news module in the place you embed it on the website. Please, specify what exactly you want to do with this code. How do you want to edit it? Which results do you want to achieve?
Thank you for replying Natashko! Sorry about that. What I wanted to do is change/edit the template or how the $LAST_NEWS$ looks like (e.g. Add an $IMG_URL1$, etc). I couldn't find the global block for $LAST_NEWS$ and edit it just like how you can edit informers.
xr4v3nx, code $LAST_NEWS$ and the template of Informers are not connected. Please, specify what exactly you want to achieve. If you want to change appearance of entries of the Site news module, it has to be done in CP->Design->Design management->Site news->Appearance of entries If this is not what you are interested in, specify the results you want to achieve.