The title field can appear in more places of the software than any other field. This page will explain many of the features that can affect the title field itself as well as control where it can appear.
Highlights of the title field:
You control the use and display on the title field site wide within many features using the following admin tool:
LISTING SETUP > FIELDS TO USE
shown in the following screenshot:
Within that screenshot you'll see:
The same controls you see above for site wide configuration can be done also on a category by category basis.
You can also have the title derived from answers within site wide optional fields if you like. This is the automatic classified auction titles featured explained more here
There are times that the title can appear mangled when using double-byte character languages like Arabic, Chinese, Cyrillic,…etc. What happens is that you may set the max character count for the title field to be 50 characters. The problem is that if you were using single byte characters (traditional western characters) you would see no issues. But with double-byte characters one character in a double-byte can count as two characters fulfilling the character count. So no as sometimes happens the double byte character count can mess with the character count and many more characters of the field be cutoff than expected. And this "character count cutoff" can happen in the "middle of a double byte character". When this happens the last character is mangled and unrecognizable. To compensate for this if you are using double-byte characters on your site expect to "double the normal character limit" for fields where you set limits. By this we mean that you may display a max of 50 characters for the title field on the client side but set the admin tool to allow 100. This allows for wiggle room if there is a discrepancy in the double-byte to character count issues so no title is mangled or cutoff before expected.