Box printing is enabled by default. Structure printing is disabled by default. Symbols containing spaces or special characters write using escaping backslashes and quoting vertical bars. Symbols are quoted with vertical bars or a leading backslash when they would otherwise print the same as a numerical constant. See section 14.3 for more information about symbol parsing.
Symbols display without escaping or quoting special characters.
Characters with the special names described in section 14.3 write using the same name. All characters display as the single-byte character value.