U+01C1 Latin Letter Lateral Click

The Wikipedia has the following information about this codepoint:

The lateral clicks are a family of click consonants found only in African languages. The clicking sound used by equestrians to urge on their horses is a lateral click, although it is not a speech sound in that context. Lateral clicks are found throughout southern Africa, for example in Zulu, and in some languages in Tanzania and Namibia. The place of articulation is not known to be contrastive in any language, and typically varies from alveolar to palatal.

The symbol in the International Phonetic Alphabet that represents a generic lateral click is ⟨ǁ⟩, a double vertical bar. Prior to 1989, ⟨ʖ⟩ was the IPA letter for the lateral clicks, and this is still preferred by some phoneticians, as the vertical bar may be confounded with prosody marks and, in some fonts, with a double lowercase L. Either letter may be combined with a second letter to indicate the manner of articulation, though this is commonly omitted for tenuis clicks with a velar rear articulation.

In official IPA transcription, the click letter is combined with a ⟨k ɡ ŋ q ɢ ɴ⟩ via a tie bar, though ⟨k⟩ is frequently omitted. Many authors instead use a superscript ⟨k ɡ ŋ q ɢ ɴ⟩ without the tie bar, again often neglecting the ⟨k⟩. Either letter, whether baseline or superscript, is usually placed before the click letter, but may come after when the release of the velar or uvular occlusion is audible. A third convention is the click letter with diacritics for voicelessness, voicing and nasalization; it does not distinguish velar from uvular lateral clicks. Common lateral clicks are:

The last is what is heard in the sound sample above, as non-native speakers tend to glottalize clicks to avoid nasalizing them.

In the orthographies of individual languages, the letters and digraphs for lateral clicks may be based on either the vertical bar symbol of the IPA, ⟨ǁ⟩, or on the Latin ⟨x⟩ of Bantu convention. Nama and most Saan languages use the former; Naro, Sandawe, and Zulu use the latter.