The script could remove `online` items in the source file.

[LuminousXLB]

Input

@article{iacr/CostanD16,
  author    = {Victor Costan and
               Srinivas Devadas},
  title     = {Intel {SGX} Explained},
  journal   = {{IACR} Cryptol. ePrint Arch.},
  year      = {2016},
  url       = {http://eprint.iacr.org/2016/086},
  timestamp = {Mon, 11 May 2020 15:55:18 +0200},
  biburl    = {https://dblp.org/rec/journals/iacr/CostanD16.bib},
  bibsource = {dblp computer science bibliography, https://dblp.org}
}

@online{trustzone,
  author  = {Arm Limited},
  title   = {Learn the architecture: TrustZone for AArch64},
  url     = {https://developer.arm.com/documentation/102418},
  urldate = {2021-12-21},
  year    = {2021}
}

Output

@article{iacr/CostanD16,
 author = {Victor Costan and
Srinivas Devadas},
 bibsource = {dblp computer science bibliography, https://dblp.org},
 biburl = {https://dblp.org/rec/journals/iacr/CostanD16.bib},
 journal = {{IACR} Cryptol. ePrint Arch.},
 timestamp = {Mon, 11 May 2020 15:55:18 +0200},
 title = {Intel {SGX} Explained},
 url = {http://eprint.iacr.org/2016/086},
 year = {2016}
}

Expected Behaviour

The unsupported online entry shall be left there as is.

[ClaireGyn]

Thanks for finding the issue. Will look into it when I have time