This has been done to death earlier in the thread. Maybe we need a FAQ thread on this. This would qualify for a VFAQ. (A sort of Europa league for FAQs. You'll know all about the Europa league, being a Chelsea fan and all.)
Their case is that we have knowingly failed to provide accounts that give a true and fair view of the financial circumstances of the club. So, taking the Etihad sponsorship as an example, their case is (a) HHSM/ADUG provided MCFC with funding that was in reality owner investment, but (b) this was dishonestly presented in the accounts as sponsorship from Etihad in order to circumvent FFP rules. The problem with the FA's case is that not only do our audited accounts show that this was actually genuine sponsorship income paid for services rendered, but so do Etihad's audited accounts. So they need to prove that this is not just a case of City getting one past our own auditors, this was basically a conspiracy at a very high level in Abu Dhabi that involved two major international companies presenting accounts that were known to be false. As has been made clear ad nauseam, this is an extremely serious allegation, that is tantamount to an actual allegation of fraud.
The consequence in limitation terms is this. I will break it down into paragraphs, that might help.
1. The arrangements between MCFC and the PL are essentially contractual, and subject to English law.
2. Unlike the UEFA rules, the PL rules do not include any limitation period. However, because the arrangements are subject to English law, the general limitation period of 6 years applies. See point 1.
3. The limitation period is however suspended in a case (I paraphrase in the interests of brevity) where fraud is alleged until the fraud comes to light. It is at that point that the 6 year period begins to run.
4. What this means is that if the PL can establish fraud, the 6 year period will not apply until the fraud came to light, which was the publication of the Der Spiegel articles in 2018.
5. To get over that hurdle, however, the PL needs to adduce very cogent evidence. And if they cannot, the ordinary 6 year rule will apply. See point 2.
6. For that reason, the charge of fraud is central to the case for two reasons: (a) because that is precisely what the PL is alleging, and (2) because if they cannot establish fraud, the complaints that pre-date 2017 (ie six years before the complaint was made) are time-barred.