how to comment multiple lines of html code? [duplicate]

Use this to comment in HTML | source

<!-- Comments go here -->

So you have:

<!-- <link rel="stylesheet" type="text/css" href="/common/css/daterangepicker-bs2.css">
<link rel="stylesheet" type="text/css" href="/common/css/multiselect.css"/>
<link rel="stylesheet" type="text/css" href="/common/app/css/tab-styles.css">
<link rel="stylesheet" type="text/css" href="/common/app/css/resumable.css">
<link rel="stylesheet" type="text/css" href="/common/app/css/connectwise.css">
<link rel="stylesheet" type="text/css" href="/app/css/chat.css">
<link rel="stylesheet" type="text/css" href="/common/app/css/remote.css">
<link rel="stylesheet" type="text/css" href="/common/app/css/screen.css"> -->

EDIT: Sorry did not realize it was CSS only. Fixed my answer.

EDIT 2: I've looked into your question again and noticed that Pete removed an important question of yours, which part you wanted to cross out. The code below should be exactly what you want.

    <link rel="stylesheet" type="text/css" href="/common/css/daterangepicker-bs2.css">
    <link rel="stylesheet" type="text/css" href="/common/css/multiselect.css"/>
    <link rel="stylesheet" type="text/css" href="/common/app/css/tab-styles.css">
    <link rel="stylesheet" type="text/css" href="/common/app/css/resumable.css">
    <!-- <link rel="stylesheet" type="text/css" href="/common/app/css/connectwise.css">
    <link rel="stylesheet" type="text/css" href="/app/css/chat.css">
    <link rel="stylesheet" type="text/css" href="/common/app/css/remote.css">
    <link rel="stylesheet" type="text/css" href="/common/app/css/screen.css"> -->

MultiLine comments are allowed in html using the

<!--   
    Sample multiline comment that can span
    across multiple lines within the html doc.
-->

However do note that comment within a comment i.e. nested comment is not supported in the same way in HTML

<!--   
    <!-- Such Nested comments are unsupported -->
    Sample of ineligible multiline comment that can span 
    across multiple lines within the html doc.
-->

In order to nest a comment, replace "--" with "- -". During un-nest, reverse the procedure. This is because the "--" is forbidden.

<!--   
    <!- - Such Nested comments are supported - ->
    Sample of eligible multiline comment that can span 
    across multiple lines within the html doc.
-->

Sed comments are lines where the first non-white character is a "#." On many systems, sed can have only one comment, and it must be the first line of the script.

In HTML a comment is placed between <!-- and -->

<!--
this
is
a (multi-line)
HTML
comment
-->

Note that most scripts ignore this comment style, as it used to help hide scripts from browsers that didn't support scripts.

so in scripts you use other commenting markings.
in js for example you can use // or /* and */

// this is a one line comment in js

/*
this is a multi line comment in js
*/

If your page passes other parsing or uses other scripts, you may need to use other markings or tags