eshell-special-chars-outside-quoting

eshell-special-chars-outside-quoting is a variable defined in `esh-arg.el'.
Its value is

(59 38 124 62 32 9 10 35 33 92 34 39)

Documentation:
Characters that require escaping outside of double quotes.
Without escaping them, they will introduce a change in the argument.

You can customize this variable.