Here below an extensive list of all FRONTEND CSS classes and ids which are hard-coded into the Joomla 1.5 core. This list could be useful to develop new modules and components, to modify joomla core code or simply to better understand the CMS css class management.

/*Frontend*/ /* FILE: components\com_contact\views\category\tmpl\default.php */

div.componentheading
div.contentpane
div.contentdescription
td.sectiontablefooter
td.sectiontableheader

* FILE: components\com_contact\views\category\tmpl\default_items.php */

a.category
td.sectiontableentry1
td.sectiontableentry2

/* FILE: components\com_contact\views\contact\tmpl\default.php */

form#selectForm
div.componentheading
table.contentpane
td.contentheading

/* FILE: components\com_contact\views\contact\tmpl\default_form.php */

form#emailForm
input#contact_name
label#contact_emailmsg
input#contact_email
input#contact_subject
label#contact_textmsg
textarea#contact_text
input#contact_email_copy
form.form-validate
div.contact_email
input.inputbox
input.required
input.validate-email
textarea.inputbox
textarea.required
button.button
button.validate

/* FILE: components\com_content\helpers\icon.php */

span.hasTip

/* FILE: components\com_content\models\article.php */

hr#system-readmore

/* FILE: components\com_content\views\archive\tmpl\default.php */

form#jForm
div.componentheading
input.inputbox
button.button

/* FILE: components\com_content\views\archive\tmpl\default_items.php */

ul#archive-list
div#navigation
li.row
h4.title
h5.metadata
span.created-date
span.author
div.intro

/* FILE: components\com_content\views\article\tmpl\default.php */

div.contentpaneopen_edit
table.contentpaneopen
td.contentheading
a.contentpagetitle
td.buttonheading
span.small
td.createdate
td.modifydate
a.readon
span.article_separator

/* FILE: components\com_content\views\article\tmpl\form.php */

input#title
input#created_by_alias
input#publish_up
input#publish_down
textarea#metadesc
textarea#metakey
table.adminform
td.key
input.inputbox
img.calendar
textarea.inputbox

/* FILE: components\com_content\views\article\tmpl\pagebreak.php */

input#title
input#alt
td.key

/* FILE: components\com_content\views\category\tmpl\blog.php */

div.componentheading
table.blog
td.article_column
div.blog_more

/* FILE: components\com_content\views\category\tmpl\blog_item.php */

div.contentpaneopen_edit
table.contentpaneopen
td.contentheading
a.contentpagetitle
td.buttonheading
span.small
td.createdate
td.modifydate
a.readon
span.article_separator

/* FILE: components\com_content\views\category\tmpl\blog_links.php */

a.blogsection

/* FILE: components\com_content\views\category\tmpl\default.php */

div.componentheading
table.contentpane
td.contentdescription

/* FILE: components\com_content\views\category\tmpl\default_items.php */

input.inputbox
td.sectiontableheader
td.sectiontableentry1
td.sectiontableentry2
td.sectiontablefooter

/* FILE: components\com_content\views\frontpage\tmpl\default.php */

div.componentheading
table.blog
td.article_column
div.blog_more

/* FILE: components\com_content\views\frontpage\tmpl\default_item.php */

div.contentpaneopen_edit
table.contentpaneopen
td.contentheading
a.contentpagetitle
td.buttonheading
span.small
td.createdate
td.modifydate
a.readon
span .article_separator

/* FILE: components\com_content\views\frontpage\tmpl\default_links.php */

a.blogsection

/* FILE: components\com_content\views\section\tmpl\blog.php */

div.componentheading
table.blog
td.article_column
div.blog_more

/* FILE: components\com_content\views\section\tmpl\blog_item.php */

div.contentpaneopen_edit
table.contentpaneopen
td.contentheading
a.contentpagetitle
td.buttonheading
span.small
td.createdate
td.modifydate
a.readon
span.article_separator

/* FILE: components\com_content\views\section\tmpl\blog_links.php */

a.blogsection

/* FILE: components\com_content\views\section\tmpl\default.php */

div.componentheading
table.contentpane
td.contentdescription
a.category
span.small

/* FILE: components\com_mailto\views\mailto\tmpl\default.php */

div.componentheading
input.inputbox
button.button

/* FILE: components\com_mailto\views\sent\tmpl\default.php */

div.componentheading

/* FILE: components\com_newsfeeds\views\categories\tmpl\default.php */

div.componentheading
table.contentpane
td.contentdescription
a.category
span.small

/* FILE: components\com_newsfeeds\views\category\tmpl\default.php */

div.componentheading
table.contentpane
td.contentdescription