Rocket.Chat/app/threads/client/flextab/thread.html

<template name="thread">
	<section class="contextual-bar__content flex-tab threads dropzone {{dragAndDrop}} {{hideUsername}}">
		<div class="dropzone-overlay {{isDropzoneDisabled}} background-transparent-darkest color-content-background-color">{{_ dragAndDropLabel}}</div>
		<div class="thread-list js-scroll-thread">
			<ul class="thread">
				{{# with messageContext}}
				{{#if isLoading}}
					<li class="load-more">
						{{> loading}}
					</li>
				{{else}}
						{{> message groupable=false hideRoles=true msg=mainMessage room=room subscription=subscription settings=settings customClass="thread-message" templatePrefix='thread-' customClass="thread-main" u=u ignored=false shouldCollapseReplies=true}}
						{{#each msg in messages}}
							{{> message hideRoles=true msg=msg room=room shouldCollapseReplies=true subscription=subscription settings=settings templatePrefix='thread-' u=u context="threads"}}
						{{/each}}
					{{/if}}
				{{/with}}
			</ul>
		</div>
		{{> messageBox messageBoxData}}
		<footer class="thread-footer">
			{{# with checkboxData }}
				<div style="display: flex;">
					{{> Checkbox . }}
				</div>
			{{/with}}
			<label for="sendAlso" class="thread-footer__text">{{ _ "Also_send_to_channel" }}</label>
		</footer>
	</section>
</template>