【转帖】valid Characters In Block Names Layer Names
 

valid characters in block names / layer names
valid characters in block names / layer names
back in opendwg days, it was necessary to strip special characters from block and layer names in order for autocad to read them correctly. is this still necessary with dwgdirect, or does the interface library handle this task for you?
this depends on dwg version.
up to r14 valid symbols are a-z, 0-9, _, $, -
starting with r15 the illegal characters are:
<> \ / " ' : ; * ? | , = `
if a file is saved to minor version (r13, r14) dd renames symbol table records having incorrect names and saves round-trip information to restore the names later.
while saving to r12 round-trip info is not saved.
sergey slezkin