To search for a particular type of pokemon in the box, you may enter @[TYPE]
For example, you could search @grass to show only grass type pokemon
To search for pokemon with a particular stat in the box, you may enter @[STAT]
For example, you could search @atk to show only pokemon with the +ATK stat. You can also search for combinations like @atkdef, @atkspe or @atkdefspe
Legendaries, Megas and Starters
Searching @legends and @mega will show only legendary and mega pokemon respectively. You may also filter non-legendary pokemon with @nonlegends
You can search for DelugeRPG starters (This includes Pichu, Pidgey and Eevee) with @starter and @starterevo for their whole evolutionary line.
You can search region-wise with the name, for example @kanto or @johto, or by the generation number with @gen1, @gen2 and so on
Trade Search and Offer specific searches
These work slightly differentlly, because you will first have to search for the pokemon you want, and then filter it with the following.
Stats filters work the same as they do in normal search. So if you wanted a dark charmander with +Atk, you would first search for Dark Charmander and then replace 'charmander' in the search box with @atk
Simlarly you can search for the pokemon only among the users in your friends list with @friends
You can search your pokemon box by nickname by starting your search with the format +[NICKNAME].
For example, if you search '+Super', then all your pokemon that have nicknames beginning with 'super' will be displayed
Pokemon with Alternate Sprites
You can filter your pokemon that have alternate sprites (female forms or pokemon specific formes that are different from the normal one) with @altsprites.
You can slso use @altspritesevo which will also show evolutions/pre-evolutions of your pokemon that have an alternate sprite. As an example, this means you can search for pichus that will evolve into the female form or the cosplay pikachus
@unown will simply show you all your unowns. This is useful for those trying to finish the pokedex