Fonts fc列表中报告的字体权重不是预期的，我应该使用什么作为Google字体？

我试图了解字体的重量，以便我可以要求从谷歌字体特定的字体重量

我已经在Ubuntu 16上安装了所有Google字体（所有TrueType），如果我安装了：

fc-list : family : weight

然后我得到这样一个结果：

Nunito,Nunito Black:weight=210
Nunito,Nunito ExtraBold:weight=205
Nunito,Nunito ExtraLight:weight=48
Nunito,Nunito Light:weight=50
Nunito,Nunito SemiBold:weight=180
Nunito Sans,Nunito Sans Black:weight=210
Nunito Sans,Nunito Sans ExtraBold:weight=205
Nunito Sans,Nunito Sans ExtraLight:weight=48
Nunito Sans,Nunito Sans Light:weight=50
Nunito Sans,Nunito Sans SemiBold:weight=180
Nunito Sans:weight=200
Nunito Sans:weight=80
Nunito:weight=200
Nunito:weight=80
OdorMeanChey:weight=80
Offside:weight=80
OFL Sorts Mill Goudy TT:weight=100
Oldenburg:weight=80
Old Standard TT:weight=200
Old Standard TT:weight=80
Oleo Script Swash Caps:weight=200
Oleo Script Swash Caps:weight=80
Oleo Script:weight=200
Oleo Script:weight=80
Open Sans Condensed,Open Sans Condensed Light:weight=50
Open Sans Condensed:weight=200
Open Sans Hebrew Condensed,Open Sans Hebrew Condensed Extra Bold:weight=205
Open Sans Hebrew Condensed,Open Sans Hebrew Condensed Light:weight=50
Open Sans Hebrew Condensed:weight=200
Open Sans Hebrew Condensed:weight=80
Open Sans Hebrew,Open Sans Hebrew Extra Bold:weight=205
Open Sans Hebrew,Open Sans Hebrew Light:weight=50
Open Sans Hebrew:weight=200
Open Sans Hebrew:weight=80
Open Sans,Open Sans ExtraBold:weight=205
Open Sans,Open Sans Light:weight=50
Open Sans,Open Sans SemiBold:weight=180
Open Sans:weight=200
Open Sans:weight=80
Oranienbaum:weight=80
Orbitron,Orbitron Black:weight=210
Orbitron,Orbitron Medium:weight=100
Orbitron:weight=200
Orbitron:weight=80
Oregano:weight=80
Orienta:weight=80
Original Surfer:weight=80
Oswald,Oswald ExtraLight:weight=48
Oswald,Oswald Light:weight=50
Oswald,Oswald Medium:weight=100
Oswald,Oswald SemiBold:weight=180

在许多情况下，默认权重似乎是80（我预计默认值为400 normal），而其他字体权重则无处不在

我曾期望fc列表报告的字体权重与本页中的“通用权重名称映射”相对应：但显然不是这样

Value   Common weight name
100 Thin (Hairline)
200 Extra Light (Ultra Light)
300 Light
400 Normal
500 Medium
600 Semi Bold (Demi Bold)
700 Bold
800 Extra Bold (Ultra Bold)
900 Black (Heavy)

所以我的第一个问题是，为什么报告的字体权重与上面的地图不一致

第二个问题，考虑到它们不匹配，而我的TrueType字体直接来自Google字体，如果我想从Google字体请求字体，我应该指定什么权重-上面映射表中的权重，还是fc列表中报告的权重