Hello all,
During more testing some examples of PR#448;
FYI, the QA-13091 is partially corrected on v1.2021.2,
It is OK, when we define a background. Thanks for PlantUML team.
But if we does not define a background, it is OK for PNG but KO for SVG:
PNG:
SVG:
(on SVG we observe white color instead of transparent for "-(0)-" or transparent or default value for "--(0", "0)--", "0)-(0" or "#-#" 
)
Thank for your support,
Regards,
Th.
