Exclude 1 post by ID or NAME from Category.php

See https://codex.www.ads-software.com/Function_Reference/query_posts

Esmi, thanks for linking. I checked that page, but it didn’t actually help as it’s talking about excluding categories instead of posts.

Not quite. You can use any of the parameters described on https://codex.www.ads-software.com/Class_Reference/WP_Query in query_posts.

Esmi, since I’m not a php programmer, could you solve the mystery for me?

I know the post has 3 as an id, that’s about it…

<?php
if( is_category( 'category-slug') :
$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
$args= array(
	''post__not_in' => array( 3 ),
	'paged' => $paged
);
query_posts($args);
endif;?>
<?php if (have_posts()) : while (have_posts()) : the_post(); ?>
[...]

Parse error: syntax error, unexpected ‘:’ in is what i’m getting

Typo – missing ). Try:

<?php
if( is_category( 'category-slug') ) :
$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
$args= array(
	''post__not_in' => array( 3 ),
	'paged' => $paged
);
query_posts($args);
endif;?>
<?php if (have_posts()) : while (have_posts()) : the_post(); ?>
[...]