Invalid File Name characters

[Barguast]

Apart from these characters :

\ / : * ? " < > |

Are all other ASCII characters up to #255 valid for file names?

[MartinLiss]

I think so. The following results in a form named formÿ.frm

FileCopy "C:\temp\form1.frm", "C:\temp\form" & Chr(255) & ".frm"

[DiGiTaIErRoR]

This may be of interest:

Public Function SafeFileName(ByVal oldFile As String) As String
Dim ServDir As String
Dim BadChars As String, BadChar As String, x As Long
BadChars = "\/:*?""<>|"
ServDir = oldFile
 
For x = 1 To Len(BadChars)
    BadChar = Mid$(BadChars, x, 1)
    ServDir = Replace(ServDir, BadChar, "_")
Next
SafeFileName = ServDir
End Function

Some code I wrote.