The navel, or belly button, was a small dent on the abdomen of all mammals whose females generate a placenta in their womb during pregnancy to feed their unborn young. It was the site of the attachment of the umbilical cord while in utero, and is sealed after birth. Navels could be found on the abdomen of Humans, Near-Humans, and some Humanoids, with the exception of the Jaffa, which the Symbiote pouch took their place.
It was not uncommon for young, attractive sentient females in the multiverse to display their bare midriffs and navels in either practical or alluring attire. For two example, Human Allied Soldier Marian Hawke wore a practical, navel-baring outfit during the battle on the desert planet of Tauris, likely to help stay cooler during the searing heat and Eve O'Sulliva wore a sexually appealing and skimpy bikini while she (and her Comrades, Alexi Scott, Lincoln Garica, Adam Walker, Ivan Johnson and Mary Scott) were on Tatooine, she most likely worse it as a means to seduce Adam, since the Transrace have internal devices that keep them either cool or warm more proficiently then most species. Many years later, Leia Organa was forced to wear a skimpy dancer's outfit in the court of Jabba the Hutt which also displayed her navel in the Tatooine Crisis. Other Notable navel-baring women included but weren't limited to Sebacean Aeryn Sun, Night Elf Tyrande Whisperwind, Sylvanas Windrunner (Pictured above), Lelith Hesperax, Hoshi Sato (during the Naboo Party) and her parallel counterpart, Allison Jakes, and Katarina Du Corteau, Nova Terra, Belle Walker, Tanya Adams, most of the female Terran Empire personel, and Natasha Shepard. Aayla Secura, though a Jedi Master, had a series of jewels embedded in her own navel during the First War, while Marian Hawke and Kit Brinny embedded them in their own navels to appear as harmless belly dancers in an attempt to evade the Jabba and Noore's guards in the Tatooine Crisis. Even other females, such as Natasha Volkova (Gil), had her navel pierced, as one would an ear.