Rocket.Chat/app/message-attachments/client/renderField.html

<template name="renderField">
    {{#if field.type}}
        <!-- a custom rendering is requested -->
        <div class="field">
            {{{specializedRendering field=field message=../..}}}
        </div>
    {{else}}
        {{#if field.short}}
            <div class="attachment-field attachment-field-short">
                <div class="attachment-field-title">{{field.title}}</div>
                {{{markdown field.value}}}
            </div>
        {{else}}
            <div class="attachment-field">
                <div class="attachment-field-title">{{field.title}}</div>
                {{{markdown field.value}}}
            </div>
        {{/if}}
    {{/if}}
</template>