Many files using this naming format are password-protected. The password is often the URL of the forum where the link was originally posted.
The "sc" prefix followed by a numeric code is a common naming scheme used by specific uploaders or "scenes" to categorize content. sc23667-HTWR.part3.rar
If you are missing part 1 or part 2, this file is unusable on its own. Ensure you have the full set to avoid "CRC Error" or "Unexpected end of archive" messages during extraction. Many files using this naming format are password-protected