Before I spend time experimenting, I thought maybe I’ll just ask:
Is there a list somewhere what the sort order is for characters in the layer pallet or the outliner?
Are there any illegal characters?
Can a name begin with a space to force it to sort earlier?
I often use special characters to organise my layers and materials and groups / components organise my data and separate them from imported file structures [eg autocad dwgs with 100’s of layers] and had no problem
For example
All my materials have a special character in front of them
“-” for new materials [-glaz, -wall-01, -wall-02, -wood-01, -tile-01 etc
“+” for landuse zoning [do a lot of urban zoning , eg +resd, +comm, +educ, +park]
“#” for functional zoning [ FOH, BOH, accommodation, spa, offices etc
[these are in predefined librarys on the server that all my staff are linked to
In layers I use
“+” to indicate major groups [+L00, +L01 +Lroof, +B01 etc]
“#” For reference layers [#grid, #dwgs, etc
“-” for objects [[-wall -flor ,-slab ,-furn etc
grew up in the DOS days when we only had 8.3 characters for file names and fan of the USA AIA keyword layer naming convention [simplified] hence you wont see any long names in my files.
I am also a lazy typist so usually all lowercase and only use - and spacebar, never _
underscore should be banned from keyboards
Microsoft and Apple are well known for altering their sorting methods in successive versions of their OS.
Consequently, many cross-platform applications implement the traditional (predictable) text string sorting method.
ASCII character codes table.pdf (113.3 KB)
That appears to be the case within SketchUp Pro 2018 for Windows.
Notice how the default numeric naming of additional Layers are sorted counter intuitively.
The addition of zero padding makes them sort in logical order.
Default Layer Name Sorting
Layer Name Sorting_Zero Padded
One (mostly forgotten) option is to sort by visibilty or, more appropiate, by color. (Windows only 
)
If you could only set the colors for multiple layers at once…
Layer0 is always first in the layer list, as it can be thought of as representing the lack of a layer rather than a layer. Other than that it’s a quite basic alphabetic sort.
