The recommended file extension is .langur.
Langur source code is always UTF-8. Anything else would be uncivilized.
A BOM is not allowed. Some shells (all?) would miss a shebang line if a BOM were present.
Whitespace allowed is the horizontal tab (9), space (32), line feed (10), and the carriage return/line feed combination (13/10).
Use a shebang line at the very start of the file to specify the interpreter to use, such as...
Comments allow characters designated as "Graphic" by Unicode or from a Private Use Area.
Langur has 2 types of comments, single-line comments and multi-line (or inline) comments. Langur does not use // for single-line comments.
# single-line comment started with hash mark /* multi-line (or inline) comment enclosed in C-style markers */