Solution 1 :

Yes, reserved entities in HTML are case sensitive.

Browsers will be nice to you and accept whatever you give them, but you should be using the proper casing.

See also:

Solution 2 :

From the below resource:

Note: HTML entities names are case-sensitive! Please check out the
HTML character entities reference for a complete list of character
entities of special characters and symbols

And From

Generally, HTML is case-insensitive, but there are a few exceptions.
Entity names (the things that follow ampersands) are case-senstive,
but many browsers will accept many of them entirely in uppercase or
entirely in lowercase; a few must be cased in particular ways. For
example, Ç is Ç and ç is ç. Other combinations of upper
and lower case are no good.

Problem :

HTML in general is case insensitive. However I`ve noticed some escape names are case sensitive. For example , Á and á.
Is & case sensitive regarding HTML standard?


Comment posted by

Note that the name is case sensitive: in HTML, Á represents the uppercase letter Á, whereas á represents the lowercase á.

Comment posted by Alex

I suppose correct one is low case: &. thank you

Comment posted by Brad

@Alex That is correct,