A “notice of pendency of action” (aka “lis pendens”) means providing notice of the pendency of a legal action in which a real property claim of title or possession is alleged.  [Code of Civil Procedure (CCP) § 405.2, 405.4]  A lis pendens is recorded against the property affected by the claim, following which any purchaser, encumbrancer, or other transferee shall be deemed to have notice of the claim. The rights and interest of the claimant, as ultimately determined in the pending noticed action, will relate back to the date the notice was recorded.  [CCP § 405.24]

Typically, prior to recordation, the lis pendens must be mailed to all parties to whom the claim is adverse, and attach  proof this mailing occurred [CCP § 405.22]  Any lis pendens that does not comply is deemed void.  [CCP § 405.23]

The law governing notices of pendency of action provides an exception for eminent domain matters.  Under the eminent domain law, the condemnor is required to record the lis pendens at the time the eminent domain action is filed, and thereafter serving a copy of the lis pendens with the summons and complaint.  [CCP §§ 405.6, 1250.150] 

Note that, should the condemnor desire to include the case number on the lis pendens, strict compliance with the requirement  that the lis pendens be recorded at the time the eminent domain action is filed is virtually impossible.  This is because a case number is only issued after the summons complaint are filed, which these days often does not occur for days (or sometimes weeks) after the pleadings are filed.