**Worktodo.txt** is the file that tells Prime95 and other related programs what work units to do and specifically what other parameters to use for that particular assignments and worktype.

The list below shows the meaning of the various entries:

- Lucas-Lehmer tests

- AdvancedTest simply LL tests the given Mersenne number, (ignoring any sort of prefactoring) and is used by Prime95 when you use the Advanced > Test option.

- Probable prime

- PRP=k,b,n,c[,how_far_factored,tests_saved][,known_factors]

- Factoring

- Factor=assignment ID,exponent,how far factored,how far to factor to
- Pfactor=assignment ID,k,b (base),n (exponent),c,how far factored,LL tests saved if factor found
- Pminus1=assignment ID,k,b,n,c,B1,B2[,B2_start][,"factors"]
- ECM2=assignment ID,k,b,n,c,B1,B2,curves to do[,specific_sigma,B2_start][,"factors"]

where k, b, n, c represent a number k × b^{n} + c. (c can take negative values.)

In programs such as mmff and feromant, there is also

- FermatFactor=nmin,nmax,kmin,kmax

Starting from v25.5 of Prime95, worktodo.txt may also contain comment lines, which are ignored by the program.

## See also