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 _
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.
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.
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.
How are 10 and 2 treated in the two places? Often 10 is considered to come before as each characters is compared individually and 1 is before 2. If one place uses so called natural sorting and the other doesn’t, that could explain why +'s position in the ‘alphabet’ differs.
In 2019 at least, the Layer palette is sorting “natural” while the pop-up layer menu in the Entity Info palette sorts as ASCII, and “Natural” is putting numbers before any characters.