Server

Maximum number of retries per server
Disconnect from Usenet server(s) when queue is empty or paused.

Queue

Used before an NZB enters the queue.
Executed after the queue finishes downloading.
mins Posts will be paused until they are at least this age. Setting job priority to Force will skip the delay.
Enable for less memory usage. Disable to prevent slow jobs from blocking the queue.
Try to predict successful completion before actual download (slower!)
When during download it becomes clear that too much data is missing, abort the job
Detect identical downloads based on name or NZB contents.
https://sabnzbd.org/wiki/duplicate-detection
Detect duplicates based on analysis of the filename.
https://sabnzbd.org/wiki/duplicate-detection
Bypass smart duplicate detection if PROPER, REAL or REPACK is detected in the download name.
In case of "Pause", you'll need to set a password and resume the job.
Select a mode and list all (un)wanted extensions. For example: exe or exe, com
Action when an unwanted extension is detected
Automatically sort jobs in the queue when a new job is added. The queue will resort every 30 seconds if % downloaded is selected.
Jobs will start unpacking during the downloading to reduce post-processing time.
Only works for jobs that do not need repair.

Post processing

Pauses downloading at the start of post processing and resumes when finished.
This prevents multiple repair runs by downloading all par2 files when needed.
Read the Wiki Help on this!
Read the Wiki Help on this!
Read the Wiki Help on this!
Do an extra verification based on SFV files.
Only unpack and run scripts on jobs that passed the verification stage. If turned off, all jobs will be marked as Completed even if they are incomplete.
Unpack archives (rar, zip, 7z) within archives.
All files will go into a single folder.
When the post-processing script returns a non-zero exit code, the job will be flagged as failed.
Filter out sample files (e.g. video samples/proofs). Delete after download.
If filenames of (large) files in the final folder look obfuscated or meaningless they will be renamed to the job name. Additionally, attempts to set the correct file extension based on the file signature if the extension is not present or meaningless.
List of file extensions that should be deleted after download.
For example: nfo or nfo, sfv

Naming

Use temporary names during post processing.
Disable when your system doesn't handle that properly.
Replace spaces with underscores in folder names.
Replace underscores with dots in folder names.
Replace dots with spaces in folder names.
For servers: make sure names are compatible with Windows.

Quota

How much can be downloaded this month (K/M/G)
Does the quota get reset each day, week or month?
On which day of the month or week (1=Monday) does your ISP reset the quota? (Optionally with hh:mm)
Should downloading resume after the quota is reset?