Lets get the whole picture here.
The fLDS is a separate sect from the mLDS (Modern LDS) which is a distinguishable sect from the dLDS (disincorporated LDS Church) which was previously the oLDS (The original LDS).
The oLDS practiced Polygamy but kept it a secret.
The dLDS church published the Revelation and not only practiced Polygamy but preached it as well. The dLDS Church became disincorporated in 1882 when the US Government began enforcing anti-Polygamy statutes.
In order to re-incorporate, the dLDS President issued a statement denying that the Mormons were engaged in any more polygamy (but the practice continued under the table until at least 1904 when the second manifesto was issued.
When the SLC dLDS Church reincorporated it became what is now the mLDS (Modern LDS).
When the second manifesto was issued saying "Hey we REALLY mean that we aren't going to be polygamists anymore" those who followed that Manifesto became the mLDS and those who continued to practice polygamy (like their predecessors the oLDS and the dLDS) became the fLDS.
Now which of these churches is not like the others.
Great explanation. I hope you have it archived for future use.