diff --git a/knowledge-base/moneropedia/address.md b/knowledge-base/moneropedia/address.md
index 5dd99bb30229ba293f974fb60a3198c8ffac9f3c..ed33f15a69c0969f7f85287f85caadf6e8e6c14d 100644
--- a/knowledge-base/moneropedia/address.md
+++ b/knowledge-base/moneropedia/address.md
@@ -7,9 +7,16 @@ summary: "either an alias, such as donate.getmonero.org, or a set of 95 characte
 
 ### The Basics
 
-When you send Monero to someone you only need one piece of information, and that is their Monero address. A *raw* Monero address is a set of 95 characters starting with a 4. The Monero donation address, for instance, is <span class="long-term">44AFFq5kSiGBoZ4NMDwYtN18obc8AemS33DBLWs3H7otXft3XjrpDtQGv7SqSsaBYBb98uNbr2VBBEt7f2wfn3RVGQBEP3A</span>.
+When you send Monero to someone you only need one piece of information, and that is their Monero address. A *raw* Monero address is a set of 95 characters starting with a '4'. The Monero donation address, for instance, is <span class="long-term">44AFFq5kSiGBoZ4NMDwYtN18obc8AemS33DBLWs3H7otXft3XjrpDtQGv7SqSsaBYBb98uNbr2VBBEt7f2wfn3RVGQBEP3A</span>.
 
-Because those addresses are long and complex you will often encounter an @OpenAlias address instead. For example, Monero donations can be sent to <span class="long-term">donate@getmonero.org</span> or <span class="long-term">donate.getmonero.org</span>
+Because those addresses are long and complex you will often encounter an @OpenAlias address instead. For example, Monero donations can be sent to <span class="long-term">donate@getmonero.org</span> or <span class="long-term">donate.getmonero.org</span>.
 
 If you would like to get an @OpenAlias address of your own then there is some information on the [OpenAlias page](/knowledge-base/openalias).
 
+### Integrated address
+
+An integrated address is an address combined with an encrypted 64-bit @payment-ID. A raw integrated address is 106 characters long.
+
+### In-depth Information
+
+The address is actually the concatenation, in Base58 format, of the *public* @spend-key and the *public* @view-key, prefixed with the network byte (the number 18 for Monero) and suffixed with the first four bytes of the Keccac-256 hash of the whole string (used as a checksum).
diff --git a/knowledge-base/moneropedia/mnemonicseed.md b/knowledge-base/moneropedia/mnemonicseed.md
index e3f517d84af6b77b8d7b8fbd9a73aa09c9e602fb..6fb47d125e6f2b4bc201d3c1b0860735245b420a 100644
--- a/knowledge-base/moneropedia/mnemonicseed.md
+++ b/knowledge-base/moneropedia/mnemonicseed.md
@@ -7,4 +7,9 @@ summary: "a 13 or 25 word phrase used to backup a Monero account, available in a
 
 ### The Basics
 
-{{ page.summary | capitalize }}.
\ No newline at end of file
+{{ page.summary | capitalize }}. This 25-word phrase (13 words in the case of MyMonero) has all the information needed to view and spend funds from a Monero @account.
+
+### In-depth Information
+
+In the official wallet, the mnemonic seed comprises 25 words with the last word being used as a checksum. Those words correspond to a 256-bit integer, which is the account's *private* @spend-key. The *private* @view-key is derived by hashing the private spend key with Keccak-256, producing a second 256-bit integer. The corresponding *public* keys are then derived from the private keys.
+
diff --git a/knowledge-base/moneropedia/paymentid.md b/knowledge-base/moneropedia/paymentid.md
index a21ab6c271ae672c10ce58157a392b5c9549b0e2..f4a7a94f0a822372d90c3e047c2a6d61875b4de4 100644
--- a/knowledge-base/moneropedia/paymentid.md
+++ b/knowledge-base/moneropedia/paymentid.md
@@ -7,11 +7,20 @@ summary: "an optional flag that is added to identify transactions to merchants,
 
 ### The Basics
 
-Payment ID is an **arbitrary** and **optional** transaction attachment that consists of 32 bytes (64 hexadecimal characters).
+Payment ID is an **arbitrary** and **optional** transaction attachment that consists of 32 bytes (64 hexadecimal characters) or 8 bytes (in the case of integrated addresses).
 
-It is usually used to identify transactions to merchants and exchanges: Given the intrinsic privacy features built into Monero, where a single public address is usually used for incoming transactions, the Payment ID is especially useful to tie incoming payments with user accounts.
+The Payment ID is usually used to identify transactions to merchants and exchanges: Given the intrinsic privacy features built into Monero, where a single public address is usually used for incoming transactions, the Payment ID is especially useful to tie incoming payments with user accounts.
+
+### Compact Payment ID's and Integrated Addresses
+
+Since the 0.9 Hydrogen Helix version, the Payment IDs can be encrypted and embedded in a payment address. The payment ID's of this type should be 64-bits.
 
 ### Creating a Payment ID
 One can create a Payment ID quickly from the command line using OpenSSL:
 
 ```# openssl rand 32 -hex```
+
+or
+
+```# openssl rand 8 -hex``` to get a PaymentID for an Integrated Address.
+
diff --git a/knowledge-base/moneropedia/spendkey.md b/knowledge-base/moneropedia/spendkey.md
index e9d045d922c0c03785bd74a427e2d7cac73a83cf..d57544d1ad9e636ad97f998ff3df4b66182fc39b 100644
--- a/knowledge-base/moneropedia/spendkey.md
+++ b/knowledge-base/moneropedia/spendkey.md
@@ -2,9 +2,15 @@
 layout: moneropedia
 entry: "Spend Key"
 terms: ["spend-key", "spend-keys"]
-summary: "one of two sets of private and public cryptographic keys that each account has, with the private spend key required to spend any funds in the account"
+summary: "one of the two pairs of private and public cryptographic keys that each account has, with the *private* spend key used to spend any funds in the account"
 ---
 
 ### The Basics
 
-{{ page.summary | capitalize }}.
\ No newline at end of file
+{{ page.summary | capitalize }}.
+
+### In-depth Information
+
+The *private* spend key is a 256-bit integer that is used to sign Monero transactions. With the current deterministic key derivation method of the official wallet, the private spend key is also an alternate representation of the @mnemonic-seed. It can be used to derive all other account keys.
+
+
diff --git a/knowledge-base/user-guides/simplewallet.md b/knowledge-base/user-guides/simplewallet.md
index abeab12a89baf592d03859eb841cec55020ea9c8..375a45ebd519f17331d5dafbff264a075e44792f 100644
--- a/knowledge-base/user-guides/simplewallet.md
+++ b/knowledge-base/user-guides/simplewallet.md
@@ -38,8 +38,7 @@ In this example, `Balance` is your total balance. The `unlocked balance` is the
 
 You will need the standard address you want to send to (a long string starting with '4'), and
 possibly a payment ID, if the receiving party requires one. In that latter case, that party
-may instead give you an integrated address, which is both of these packed into a single address
-(integrated address do not start with 4, but A).
+may instead give you an integrated address, which is both of these packed into a single address.
 
 ### Sending to a standard address: