From Bulbapedia, the community-driven Pokémon encyclopedia.
Ranger Signs (Japanese: レンジャーサイン Ranger Sign), also known as involiths or emblems are only featured in Pokémon Ranger: Guardian Signs. They allow players to draw symbols on the ground with their Capture Styler to summon Pokémon, such as the Legendary beasts and the Eon duo.
In the games
Ranger Signs can be obtained by capturing Legendary Pokémon, completing quests, or manually entering special signs into the Styler via the Sign List. The player can only start to use them when Nema 'illegally' modifies the player's Capture Styler.
These Ranger Signs are obtained as players continue through the story. They are needed in order to complete the game. Only the Legendary beasts and the Eon duo can be ridden. They also have additional capabilities only shown when the Capture Styler is charged when summoning them. Latias is only obtained if the player has chosen to play as the female character. Latios is present if the male character is chosen. The Involiths of Raikou, Entei, and Suicune are stolen by the Pokémon Pinchers to gain access to Articuno, Zapdos, and Moltres. The hero regains the stolen part of the Involiths later in a side quest for Weber, and reattaches the stolen parts to the Involiths.
These Ranger Signs are obtained only after finishing certain quests. Once summoned, they will join the player's party. Only one friend Pokémon can join the player at any one time. While the Field Moves of the summoned Pokémon are the lowest possible, their Poké Assists are more powerful than those of the Pokémon found in the wild.
These Ranger Signs are not available in-game, with the exception of Mewtwo, whose Ranger Sign can be seen in the game intro. To unlock them, they need to be input into the Styler's sign list manually by selecting the question mark icon at the end of the list and drawing the sign when prompted. However, the player must have recorded the Pokémon's data on their browser before the sign can be registered. They are revealed through various means, such as by official sites and magazines. The Pokémon summoned are similar to those summoned from Ranger Signs obtained from quests. All Pokémon called by these signs have their Field Abilities reduced to level 1.
In the anime
The Ranger sign is described as a way to summon Pokémon the Ranger captured in the past. The Ranger Sign first made a brief appearance in the anime in the second Guardian Signs anime special, where it was sought after and acquired by the Pokémon Pinchers.
In Pokémon Ranger: Heatran Rescue!, Ben used it to summon a Feraligatr twice.