> ## Documentation Index
> Fetch the complete documentation index at: https://docs.zeotap.com/llms.txt
> Use this file to discover all available pages before exploring further.

# How does the Strategy Work

> In this strategy, as explained above, you can classify your identifiers as Primary or Secondary identifiers or Disable an ID from participating in ID resolution.

When a new data record is received, based on how you have classified your identifiers, the system looks up the existing profiles and performs the actions mentioned below.

| **SCENARIO**                                                         | **SCENARIO**              | **ACTION**                                                                                                                                                                                                                                                                                          |
| :------------------------------------------------------------------- | :------------------------ | :-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| If a Primary ID exists                                               | Match not found           | Create a new user profile. (UCID)                                                                                                                                                                                                                                                                   |
| If a Primary ID exists                                               | One match found           | For the same UCID, enrich the existing profile with user traits,consent, identifiers and events received in the record.                                                                                                                                                                             |
| If a Primary ID exists                                               | More than one match found | Reconciliation logic<ul><li><p>The UCID that was created first is picked as the master UCID.</p></li><li><p>All the other UCIDs are reconciled to the master UCID.</p></li><li><p>All the corresponding user traits, consent, identifiers and events are mergedinto the master UCID.</p></li></ul>  |
| If only a Secondary ID exists                                        | Match not found           | Create a new user profile (UCID).                                                                                                                                                                                                                                                                   |
| If only a Secondary ID exists                                        | One match found           | Enrich the existing profile with user traits, consent, identifiers,events and more.                                                                                                                                                                                                                 |
| If only a Secondary ID exists                                        | More than one match found | Reconciliation logic<ul><li><p>The UCID that was created first is picked as the master UCID.</p></li><li><p>All the other UCIDs are reconciled to the master UCID.</p></li><li><p>All the corresponding user traits, consent, identifiers and events are merged into the master UCID.</p></li></ul> |
| If all the incoming IDs are disabled or no ID is found in the record |                           | Reject the record and log it as an erroneous record                                                                                                                                                                                                                                                 |

<Note>
  **Note:**

  The above table explains a scenario where the ID prioritisation feature is not used. That is, all the IDs within a classification (Primary or Secondary) are treated the same.

  *Disable ID is a new feature and is currently available in the Beta phase. However, if you want to be a part of our Beta phase, then reach out to your Zeotap POC.*
</Note>

**Example**

We are considering the following ID classification to further explain the use cases for ID Classification:

| **IDENTIFIER** | **CLASSIFICATION** |
| :------------- | :----------------- |
| `User ID`      | Primary            |
| `Email`        | Primary            |
| `MAID`         | Secondary          |
| `GA client ID` | Secondary          |
| `TTD Cookie`   | Disabled           |

<Note>
  **Note:**

  In this use case, the priority of these IDs are same within their classification.
</Note>

| **USE CASE**                                                        | **DATA SCENARIO**                                                                                    | **WHAT DOES ZEOTAP DO?**                                                                                                                                                                                                                                                                                                                                       | **PROFILE CREATED**                                               |
| ------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------- |
| User A logs into the Brand’s mobile app 1                           | `User ID: U1` <br /><br /> `Maid: M1`                                                                | 1.  Among the identifiers received, U1 is a Primary identifier. <br /><br /> 2.  The system looks up a match for U1. <br /><br /> 3.  With no match found, it creates a new UCID: Z1. <br /><br /> 4.  It also creates linkages with all the other identifiers and maps the other information like profile, event and consent and more received in the record. | `Z1 {User ID: U1Maid: M1}`                                        |
| User A logs into the Brand's app 1  using a different mobile device | `User ID: U1` <br /><br /> `Maid: M2`                                                                | 1.  As U1 is a Primary identifier, the system looks up a match for U1. <br /><br /> 2.  It finds a match for U1. <br /><br /> 3.  It updates the profile, Z1 with the new ID linkages and the other information received.                                                                                                                                      | `Z1 {User ID: U1Maid: M2}`                                        |
| User A logs into the Brand's app 2  using the same mobile device    | `Email: E1` <br /><br /> `Maid: M2`                                                                  | 1.  As E1 is a Primary identifier, the system looks up a match for E1.   <br /><br /> 2.  With no match found, it creates a new UCID: Z2. <br /> <br /> 3.  It also creates linkages with all the other identifiers and maps the other   information like profile, event and consent and more      received in the record.                                     | `Z2 {Email: E1Maid: M2}`                                          |
| User A logs into the Brand's website                                | `User ID: U1` <br /><br /> `Email: E1` <br /><br /> `GA Client ID: G1` <br /><br /> `TTD cookie: T1` | 1.  As both U1 and E1 are      Primary IDs, the system      looks up for a match with      both the IDs and finds Z1      and Z2. <br /><br /> 2.  In this case        , the profile      with the first created UCID      that is, Z1 is retained as the      master profile and the other      matched profile, that is Z2 is      merged to it.             | `Z1 {User ID: U1Email: E1Maid: M2GA Client ID: G1TTD cookie: T1}` |
| -                                                                   | `TTD cookie: T1`                                                                                     | If a record contains no  Primary or Secondary  identifiers and  just has the  disabled identifiers or no  identifier at all, then Zeotap  rejects such a record and  logs it as an erroneous  record.                                                                                                                                                          | No profile is created  or updated                                 |