#fontSelectionStrategy N.B. that (1) line height normal is resolved against a paragraph's font families, including implementation defined fall back fonts; (2) the TTML2 spec (10.2.27) presently says that the font selected from these families, F0, is the "the first font obtained when sequentially mapping each font family in FF to a set of available fonts" and that this mapping is constrained by tts:fontSelectionStrategy; (3) this specification test does not specify what content to use when performing this mapping: e.g., the entire paragraph's content, the first character of the paragraph, etc., are among the possibilities; (4) CSS Fonts Module Level 4 defines "first available font" as the first font whose unicode-range includes the U+0020 (SPACE) character (regardless of whether that font has a mapping of this character to a glyph); (5) finally, the semantics of tts:fontSelectionStrategy="auto" are implementation dependent, and may very well be the same as tts:fontSelectionStrategy="character"; (6) as a result of the aforesaid, this test is not necessarily portable among different implementations: more specifically, the expectations file associated with this test was produced by an implementation that assigns F0 to the first font in the font family list specified below, namely, "PT Mono", regardless of paragraph content, and, as such, resolves tts:lineHeight="normal" to the same value regardless of the setting of tts:fontSelectionStrategy (on the paragraph).