U+2C60 Latin Capital Letter L with Double Bar

The Wikipedia has the following information about this codepoint:

The voiceless velar lateral fricative is a rare speech sound. As one element of an affricate, it is found for example in Zulu and Xhosa (see velar lateral ejective affricate). However, a simple fricative has only been reported from a few languages in the Caucasus and New Guinea.

Archi, a Northeast Caucasian language of Dagestan, has four voiceless velar lateral fricatives: plain [𝼄], labialized [𝼄ʷ], fortis [𝼄ː], and labialized fortis [𝼄ːʷ]. Although clearly fricatives, these are further forward than velars in most languages, and might better be called prevelar. Archi also has a voiced fricative, as well as a voiceless and several ejective lateral velar affricates, but no alveolar lateral fricatives or affricates.

In New Guinea, some of the Chimbu–Wahgi languages such as Melpa, Middle Wahgi, and Nii, have a voiceless velar lateral fricative, which they write with a double-bar el (Ⱡ, ⱡ). This sound also appears in syllable coda position as an allophone of the voiced velar lateral fricative in Kuman.

The extIPA has the letter ⟨𝼄⟩ for this sound. It was added to Unicode in 2021.

Some scholars also posit a voiceless velar lateral approximant distinct from the fricative. The approximant may be represented in the IPA as ⟨ʟ̥⟩.