The following steps are executed for each "sibling" that has been found with all of the following characteristics:

1. Input animal has not previously been rejected
2. Same dam as input dam
3. Birth date within 273 days of input birth date
4. Input animal is not designated as ET or clone

STEP 1 -- Sire comparison:

• If sires of input animal and "sibling" are unequal:
  1. if "sibling" is ET or clone, assume they are two animals and continue with next "sibling"
  2. if source of input animal is 'I', assume they are two animals and continue with next "sibling"
  3. otherwise generate a 1Ma reject error code

STEP 2 -- Birth date comparison:

• If birth dates of input animal and "sibling" are unequal, but within 273 days:
  1. if "sibling" is ET or clone, assume they are two animals and continue with next "sibling"
  2. if source of input animal is 'I', assume they are two animals and continue with next "sibling"
  3. if either birth date is estimated, generate a 1Mb notify error code
  4. if either birth date is zero birth day, generate a 1Mb notify error code
  5. if birth dates are within 10 days, generate a 1Mb notify error code
  6. if birth dates NOT within 10 days, generate a 1Mc reject error code

STEP 3 -- Gender comparison:

• if genders of input animal and "sibling" are unequal, assume they are two animals ¹

STEP 4 -- Lactation comparison; females only:

• if calving date of input animal will not merge with "sibling's" lactations, assume they are two animals ¹
• if pre-existing lactations of both animals will not merge, assume they are two animals ¹

STEP 5 -- Calving date comparison; females only:

• if both animals are singletons and they have a common calving date:
  1. if breed codes and 12-byte IDs are equal, but country codes are unequal, re-id to one animal ^{3 4}
  2. if country codes and 12-byte IDs are equal, but breed codes are unequal, re-id to one animal ^{3 4}
  3. if 12-byte IDs are within 99 digits, assume they are two animals. Merge lactations only ¹
  4. otherwise cross reference to one animal ²

STEP 6 -- Country code comparison as only difference:

• if breed codes and 12-byte IDs are equal, but country codes are unequal, re-id to one animal ^{3 4}

STEP 7 -- Breed code comparison as only difference:

• if country codes and 12-byte IDs are equal, but breed codes are unequal, re-id to one animal ^{3 4}

STEP 8 -- Multiple cross references:

• if there is more than one "sibling" that is NOT a singleton and input animal is a singleton, generate a 1Mk reject error code

STEP 9 -- 99 digit range ID comparison:

• if 12-byte IDs are within 99 digits, assume they are two animals ¹

STEP 10 -- Multiple birth comparison:

• if input animal is a twin or "sibling" is a twin/ET/clone, assume they are two animals ¹

STEP 11 -- Similar ID comparison:

• if 12-byte IDs are "similar" (i.e. ID is shifted right one position)
  1. get highest source of data from each animal (highest to lowest; B,N,I,D,C,A)
  2. if one animal ID has a higher source of data, re-id to one animal ⁴ (the lower source supplied ID is deleted)
  3. if source of both animal IDs is breed associatons, assume they are two animals ¹
  4. otherwise re-id to one animal ⁴ (the "sibling" ID is deleted)

STEP 12 -- Country code comparison:

• if country codes are unequal, cross reference to one animal ²

STEP 13 -- Breed code comparison:

• if breed codes are unequal, cross reference to one animal ²
• NLD country code animals must have the same last 7 digits to cross reference

STEP 14 -- Prefix of ID comparison:

• if first 5-bytes of IDs indicate IDs are from different series, cross reference to one animal ²

STEP 15 -- Remaining animals:

• assume they are two animals ¹

-----------------------------------------------------------------------

¹ Animal IDs assumed to be two animals -- Designate unidentified twin

• if both animals are singletons, change both animals to twins, and generate a 1Mf notify error code
• if sibling is a singleton and input is a twin, change the sibling to a twin, and generate a 1Mh notify error code
• if sibling is a twin and input animal is a singleton, change the input animal to a twin, and generate a 1Mg notify error code

² Animal IDs assumed to be one animal -- Generate unidentified cross reference ID

• merge data from both animals and generate a 1Md notify error code
• if merged birth date is not the input birth, update the birth date, and generate a 1Mi notify error code

³ Animal IDs assumed to be one animal -- Determine misidentified ID

• get highest source of data from each animal (highest to lowest; B,N,I,D,C,A)
• if one animal ID has a higher source, the lower source supplied ID is deleted
• otherwise the "sibling" ID is deleted

⁴ Animal IDs assumed to be one animal -- Remove misidentified ID

• merge data from both animals and generate a 1Md notify error code
• if merged birth date is not the input birth, update the birth date, and generate a 1Mi notify error code
• if the input ID is the misidentified ID, delete the 17-byte input ID, and generate a 1Me notify error code
• if the "sibling" ID is the misidentified ID, delete the 17-byte "sibling" ID and generate a 1Mj notify error code