At least OpenSCAD and FreeCAD (and probably other applications capable of producing ASCII STL) do not place space after the word solid when it's not followed by name.
(The only article saying that the space should always follow the word solid is the one on Wikipedia and I haven't yet found such information in any of the cited sources.)
https://github.com/mkeeter/fstl/blob/d021118ee2f162c2e487c5454f51589d1797fdc1/src/loader.cpp#L120
At least OpenSCAD and FreeCAD (and probably other applications capable of producing ASCII STL) do not place space after the word solid when it's not followed by name.
(The only article saying that the space should always follow the word solid is the one on Wikipedia and I haven't yet found such information in any of the cited sources.)