WIP docs: Get rid of "initialized for signing" terminology

Author: real-or-random

include/secp256k1.h

@@ -217,11 +217,10 @@ typedef int (*secp256k1_nonce_function)(
 /** A built-in constant secp256k1 context object with static storage duration, to be
  *  used in conjunction with secp256k1_selftest.
  *
- *  This context object is *not* "initialized for signing", i.e., it cannot be used
- *  for certain functions that operate on secret keys, e.g., signing and public key
- *  generation. See secp256k1_context_create if you need a context object initialized
- *  for signing.
+ *  This context object offers *only limited functionality* , i.e., it cannot be used
  *  for most functions that operate on secret keys, e.g., signing and public key
+ *  generation. See secp256k1_context_create if you need a context object that does
+ *  not have this limitation.
  *
  *  It is highly recommended to call secp256k1_selftest before using this context.
  */
@@ -258,18 +257,18 @@ SECP256K1_API void secp256k1_selftest(void);
  *  secp256k1_preallocated.h.
  *
  *  Returns: a newly created context object.
- *  In:      flags: which parts of the context to initialize. Set this to
- *                  SECP256K1_CONTEXT_SIGN, see below.
+ *  In:      flags: configuration flags. Set this to
+ *                  SECP256K1_CONTEXT_DEFAULT, see below.
  *
- *  Currently, the only valid non-deprecated flag is SECP256K1_CONTEXT_SIGN, which will
- *  create a context "initialized for signing". This is sufficient for all functionality
+ *  Currently, the only valid non-deprecated flag is SECP256K1_CONTEXT_DEFAULT, which will
+ *  create a context sufficient for all functionality
  *  currently offered by the library. All other (deprecated) flags will be treated as
- *  equivalent to SECP256K1_CONTEXT_SIGN. Though the flags parameter primarily exists
+ *  equivalent to SECP256K1_CONTEXT_DEFAULT. Though the flags parameter primarily exists
  *  for historical reasons, future versions of the library may introduce new flags.
  *
  *  If the context is intended to be used for functions that operate on secret keys,
  *  e.g., signing and public key generation (or strictly speaking, all functions that are
- *  documented to require a context "initialized for signing"), then it is highly
+ *  documented to require a context which is not the static context), then it is highly
  *  recommended to call secp256k1_context_randomize on the context before calling these
  *  functions. This will provide enhanced protection against side-channel leakage.
  */
@@ -628,7 +627,7 @@ SECP256K1_API extern const secp256k1_nonce_function secp256k1_nonce_function_def
  *
  *  Returns: 1: signature created
  *           0: the nonce generation function failed, or the secret key was invalid.
- *  Args:    ctx:       pointer to a context object, initialized for signing.
+ *  Args:    ctx:       pointer to a context object (not secp256k1_context_static).
  *  Out:     sig:       pointer to an array where the signature will be placed.
  *  In:      msghash32: the 32-byte message hash being signed.
  *           seckey:    pointer to a 32-byte secret key.
@@ -672,7 +671,7 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_seckey_verify(
  *
  *  Returns: 1: secret was valid, public key stores.
  *           0: secret was invalid, try again.
- *  Args:    ctx:    pointer to a context object, initialized for signing.
+ *  Args:    ctx:    pointer to a context object (not secp256k1_context_static).
  *  Out:     pubkey: pointer to the created public key.
  *  In:      seckey: pointer to a 32-byte secret key.
  */