In Jainism, every Tirthankar (including the 24 Tirthankaras) is associated with a unique emblem or sign, known as a lanchhan. These signs are part of the traditional iconography and help identify each Tirthankar in temples, scriptures, and art.

How they got their signs:

• The lanchhan is tied to the Tirthankar’s life-story and is revealed as part of their spiritual symbolism after they attain kevala jnana (omniscience) and complete their great penance.
• The signs are fixed for each Tirthankar and are used to distinguish them across Jain traditions. They’re mentioned and described in Jain sutras and canonical*/traditional lists, and they’re used consistently by both Digambar and Shwetambar communities, though tiny iconographic or textual details may vary by tradition.

If you’d like, I can summarize the exact emblem for each of the 24 Tirthankaras (and note any small Digambar vs. Shwetambar differences) and provide brief notes on what each emblem is thought to symbolize.